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Understand the science of pet dermatology.

COLUMN EDITOR COLUMN EDITOR Craig E. Grifﬁn, DVM, DACVD Animal Dermatology Clinic, San Diego, California

COLUMN EDITOR COLUMN EDITOR Wayne S. Rosenkrantz, DVM, DACVD Animal Dermatology Clinic, Tustin, California

Overview of Flea Allergy Dermatitis ❯❯ Andrea Lam, DVM

❯❯ Anthony Yu, DVM, MS, DACVDa

University of California Davis Veterinary Medical Teaching Hospital

lea allergy dermatitis, or flea-bite hypersensitivity, is the most common small animal dermatologic condition.1–3 In some regions of the world, it is the most commonly seen canine disease. This disease does not exist in locations that are inhospitable to fleas, such as those at elevations above 1500 ft or with low humidity (e.g., the desert). Although there are more than 2000 documented species and subspecies of fleas, the cat flea (Ctenocephalides felis felis) is the species most frequently found infesting dogs, cats, and all caged pets in North America.

Flea Facts

At a Glance Flea Facts Page 220

Pathogenesis Page 220

Diagnosis Page 222

Treatment Page 223

Flea Control Products Page 224

a Dr. Yu discloses that he has received ﬁnancial support from Greer Laboratories, Iams, Novartis Animal Health, and Pﬁzer Animal Health.

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The life cycle of the flea ranges from as few as 12 to as many as 190 days, with an average of 21 days. The time needed for development depends heavily on environmental conditions, particularly temperature and humidity. The optimal environment is a low-altitude geographic location, a temperature of 75°F (23.8°C), and a relative humidity of 78%. An adult flea takes its first blood meal from a host within minutes of contact. Female fleas lay their first egg 24 to 36 hours after this blood meal. Flea eggs are smooth and slick. Only 30% of eggs remain on the haircoat; the remainder fall off the host into the environment. Hatching takes place within 1 to 10 days, again depending on humidity and temperature. A single female flea can lay 1000 eggs within 30 days, and most average 2000 eggs during their life. Although eggs can hatch anywhere in the environment, development of the larvae that emerge from the eggs must take place off the host because mammalian body temperatures are too high for survival. Larvae are highly sensitive to heat and desiccation and therefore tend to move downward and away from direct light

University of Guelph Ontario Veterinary College

sources. The larvae feed on adult flea feces (partially digested blood) in the environment. Within 5 to 11 days, a larva undergoes two separate molting stages before forming a pupa. The pupal stage is the most resilient of all stages because the cocoon is highly resistant to desiccation. It also has a sticky surface that helps to prevent premature removal from the environment and that accumulates dust and other household particulates to provide protection. On average, the pupal stage lasts 8 to 9 days; however, fleas can pupate for up to 6 months if the environmental conditions are not ideal for emergence. Only with proper environmental stimuli, such as an increase in carbon dioxide, warmth, physical pressure, and vibration, will an adult flea emerge from its cocoon. After emerging from the cocoon, adult fleas search for an appropriate host. Adult fleas are attracted to light and tend to migrate upward toward surfaces where contact with an appropriate host is more likely. Once a host is found, feeding and mating take place within 8 to 24 hours. Female fleas can consume 15 times their body weight in blood per day. Adult fleas act as obligate, permanent ectoparasites, preferring to remain on a host rather than in the environment.

Pathogenesis Flea saliva contains histamine-like compounds, proteolytic enzymes, and anticoagulants. These proteins are released into the host during feeding and can act as inflammatory or antigenic stimuli in sensitive animals. Various immunologic responses are provoked, including immediate and delayed hypersensitivity reactions,4 late-phase IgE-mediated responses, and cutaneous basophil hypersensitivity reactions.5 Dogs with atopic dermatitis appear to be predisposed to the development of ﬂea allergy dermatitis.6,7

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Dr. Yu (shown here with his dogs [from left to right] Timmy, Joey, and Bitsy) is associate professor of dermatology at The University of Guelph Ontario Veterinary College in Canada.

WEB EXCLUSIVE An extended version of this article is available on

CompendiumVet.com.

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FIGURE 1

FIGURE 2

Typical distribution pattern of ﬂea allergy dermatitis affecting the caudodorsolumbar region and caudal thighs (caudal to the “waistline”).

A ﬁbropruritic nodule, a benign hyperplastic reaction to severe flea allergy dermatitis, on a dog.

Diagnosis

QuickNotes History and physical examination ﬁndings are the keys to making an appropriate diagnosis of ﬂea allergy dermatitis.

History and physical examination findings are the keys to making an appropriate diagnosis of flea allergy dermatitis. There is no breed or sex predilection, and flea allergy dermatitis can develop in animals of any age. Patients may exhibit seasonal or year-round pruritus, depending on their geographic location. The owner may report an increase in pruritus following the introduction of a new pet or a visit to a boarding or grooming facility. Often, clinical signs manifest on the caudal aspect of the animal, especially in dogs (FIGURE 1). Evidence of self-induced alopecia; erythema; pyotraumatic dermatitis; dull, coarse

FIGURE 3

“Hot spot” or acute moist traumatic dermatitis. One of the common underlying etiologies of this condition is flea allergy or flea-bite hypersensitivity.

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haircoat; hyperpigmentation; and/or lichenification may be observed affecting the dorsal lumbosacral region, tail base, caudomedial thighs, inguinal region, and umbilical fold.1 Other physical examination findings include papules or encrusted papules, crusting, scaling, and, occasionally, fibropruritic nodules (FIGURE 2) in association with affected areas. Secondary superficial to deep pyodermas are common (FIGURE 3). Close examination of the skin and haircoat using a flea comb may reveal flea dirt or adult fleas (FIGURE 4). Some pets may even exhibit clinical anemia as a result of severe flea infestation (FIGURE 5). Pets that are fastidious groomers can ingest adult fleas

FIGURE 4

Flea comb. This is a useful tool to demonstrate fleas and flea dirt to clients who are in denial about the presence of fleas on their pet.

Compendium: Continuing Education for Veterinarians® | May 2009 | CompendiumVet.com

carrying the tapeworm Dipylidium caninum and may have segments of D. caninum in their feces. Clinical manifestations of flea allergy dermatitis in cats can include miliary dermatitis, eosinophilic granulomas or plaques, or self-induced alopecia without active lesions (FIGURE 6). Affected areas may include the dorsum, inguinal region, caudomedial thighs, head, and neck. A lack of fleas or flea dirt is commonly reported by owners and should not override a diagnosis of flea allergy dermatitis if clinical suspicion is high. Intradermal skin testing with flea allergen may reveal wheal formation with immediate and delayed hypersensitivity. Serum in vitro testing for flea-specific IgE has variable accuracy and does not identify animals with delayed hypersensitivity reactions. Histopathology is nonspecific and reveals a superficial perivascular inflammation, often containing eosinophils—a pattern that can be seen in other hypersensitivity reactions.

Treatment Based on current knowledge of flea biology, topical or systemic flea adulticide therapy may be the only management required to establish adequate control over flea infestations. Many prescription flea control products are currently available (TABLE 1). Ideally, integrated pest management, including the use of flea adulticides along with insect growth regulators

(IGRs) or insect development inhibitors (IDIs), should be used as a long-term management program to effectively eradicate infestation while minimizing potential drug resistance. If the environment is heavily burdened with various stages of fleas, environmental control is also warranted. Vibrations from a vacuum cleaner help stimulate emergence of the adult flea from the impervious pupa and, hence, increase the likelihood of effective environmental ectoparasiticide control. One to two applications of a synthetic pyrethroid or fipronil as an environmental spray every 7 days should be sufficient, although the addition of a household IGR such as methoprene or pyriproxyfen and/or sodium polyborate in carpeted areas would produce the best results in the house. To avoid any potential adverse reactions, it is best to remove pets from the treated environment until the products have dried; therefore environmental treatment is often done in stages. Professionally licensed exterminators should be considered for yards and households that are heavily infested. All blankets, bedding, and rugs that are favored by the affected pet should be laundered. All carpeted areas and furniture that can house preadult fleas should be vacuumed, and the vacuum bag should be disposed of immediately. All household pets should be prevented access to flea-dense areas, such as porches, garages, and crawl spaces. Contact

QuickNotes A lack of fleas or flea dirt should not override a diagnosis of flea allergy dermatitis if clinical suspicion is high.

FIGURE 5 Severe ﬂea infestation.

Fleas on a dog before treatment.

When the dog was bathed, the water turned red from the extreme amount of flea dirt in the haircoat.

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TABLE 1

Flea Control Products Approved by the US Environmental Protection Agency and/or the US Food and Drug Administrationa Product (Manufacturer)

Active Flea Control Ingredientsb

Species and Minimum Age

Program/Sentinel (Novartis Animal Health)

Lufenuron

Dogs: 4 weeks

Frontline Plus (Merial)

Fipronil

Dogs: 8 weeks

S-Methoprene

Cats: 8 weeks

Cats: 6 weeks

Dosage/Administration

Mode of Action

Monthly oral; also injectable q6mo feline product

Inhibitor of chitin biosynthesis

Monthly spot-on

Fipronil: GABA-gated chloride channel antagonist S-methoprene: Juvenile hormone analogue (IGR)

Advantage (Bayer Animal Health)

Imidacloprid

Advantage Multi (Bayer Animal Health)

Imidacloprid

K9 Advantix (Bayer Animal Health)

Imidacloprid

Dogs: 7 weeks Cats: 8 weeks Dogs: 7 weeks

Monthly spot-on; can be used weekly

Nicotinic acetylcholine-receptor antagonist

Monthly spot-on

Nicotinic acetylcholine-receptor antagonist

Monthly spot-on

Nicotinic acetylcholine-receptor antagonist

Cats: 9 weeks (do not use canine product on cats) Dogs: 7 weeks

Permethrin

Permethrin: Sodium channel modulator Revolution (Pﬁzer Animal Health)

Selamectin

ProMeris for dogs (Fort Dodge Animal Health)

Metaﬂumizone

ProMeris for cats (Fort Dodge Animal Health)

Dogs: 8 weeks

Monthly spot-on

Chloride channel activator

Dogs: 8 weeks

Monthly spot-on

Voltage-dependent sodium channel blocker

Metaﬂumizone

Cats: 8 weeks

Monthly spot-on

Voltage-dependent sodium channel blocker

Comfortis (Eli Lilly)

Spinosad

Dogs: 14 weeks

Monthly chewable tablet

Nicotinic acetylcholine-receptor agonist (spinosyn)

Capstar (Novartis Animal Health)

Nitenpyram

Dogs: 4 weeks and 2+ lb

One tablet prn or daily/EOD

Nicotinic acetylcholine-receptor antagonist

Vectra 3D for Dogsc (Summit VetPharm)

Dinotefuran

Monthly spot-on

Dinotefuran: Nicotinic acetylcholinereceptor antagonist

Cats: 8 weeks

Cats: 4 weeks and 2+ lb Dogs: 7 weeks

Permethrin

Permethrin: Sodium channel modulator

Pyriproxyfen

Pyriproxyfen: Juvenile hormone analogue (IGR) Vectra for Cats & Kittens (Summit VetPharm)

Dinotefuran

Cats: 8 weeks

Monthly spot-on

Pyriproxyfen

Dinotefuran: Nicotinic acetylcholinereceptor antagonist Pyriproxyfen: Juvenile hormone analogue (IGR)

Adapted with permission from Mark Grossman and Carol Foil, Veterinary Information Network 2008. For the complete chart, visit www.vin.com/Link.plx?ID=37277. (EOD = every other day; prn = as needed)

Ingredients active against other parasites not listed.

This chart reﬂects the latest revision by VIN in September 2008. Please note that the following product has since become available: Vectra for Dogs and Puppies.

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FIGURE 6 Common reaction patterns associated with underlying ﬂea allergic dermatitis in cats.

QuickNotes

Miliary dermatitis of the dorsum.

Self-induced alopecia of the ventral abdomen.

with feral cats, wildlife, and other unknown neighborhood animals should be prevented. Eliminating all secondary bacterial and Malassezia infections provides short-term relief of pruritus. Shampoo therapy and short courses of oral corticosteroids are good adjunctive

therapies. Antihistamines and essential fatty acids are not effective in ﬂea-allergic patients. Finally, all animals in the household must be treated with ectoparasiticide therapy to prevent reestablishment of ﬂea populations and perpetuation of disease.

Topical or systemic ﬂea adulticide therapy may be the only management required to establish adequate control over ﬂea infestations.

References 1. Scott DW, Miller WH, Griffin CE. Skin immune system and allergic skin disorders. In: Scott DW, Miller WH, Griffin CE, eds. Muller and Kirk’s Small Animal Dermatology. 6th ed. Philadelphia: WB Saunders; 2001:543-666. 2. Cole LK. Fleas and flea allergy dermatitis. 6th Proc World Congr Vet Dermatol 2008:119-125. 3. Dryden MW. Flea and tick control in the 21st century: challenges and opportunities. Vet Dermatol 2008;19(suppl 1):12. 4. Gross TL, Halliwell RE. Lesions of experimental flea bite hyper-

APPLIED DERMATOLOGY WEB EXCLUSIVE

sensitivity in the dog. Vet Pathol 1985;22:78-81. 5. Halliwell RE, Preston JF, Nesbitt JG. Aspects of the immunopathogenesis of ﬂea allergy dermatitis in dogs. Vet Immunol Immunopathol 1987;17:483-494. 6. Kwocka KW. Fleas and related disease. Vet Clin North Am Small Anim Pract 1987;17:1235-1262. 7. Reedy LM, Miller WH. In: Reedy LM, Miller WH, eds. Allergic Skin Diseases of Dogs and Cats. Philadelphia: WB Saunders: 1989:171-187.

Otitis externa is another common, often frustrating, dermatologic condition. Visit CompendiumVet.com for one expert’s approach to canine otitis externa, “A Practical Approach to Diagnosing and Managing Ear Disease in Dogs,” by Paul Bloom, DVM, DACVD, DAVBP (Canine and Feline).

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SERIES EDITOR Craig E. Grifﬁn, DVM, DACVD Animal Dermatology Clinic, San Diego, California

SERIES EDITOR Wayne S. Rosenkrantz, DVM, DACVD Animal Dermatology Clinic, Tustin, California

Diagnosing the Cause of Feline Pruritus ❯❯ Rudayna Ghubash, DVM, DACVD Animal Dermatology Clinic Marina del Rey, California

iagnosing the underlying cause of pruritus in cats can be considered. Food allergy can start at any age. be difficult because of the variations in clinical pre- Some breeds are predisposed to certain diseases, such as Persians (dermatophytosis) and sentation and numerous possible etiologies. Many own- Siamese (food allergies)1–3 (FIGURE 1). ers are not aware of how much their cats lick and groom themselves, making it difficult to assess the cat’s degree Environment of pruritus. The ability to interpret historical information, Outdoor cats have greater exposure to mosquitoes (FIGURE 2), parasites (e.g., fleas, Notoedres identify and understand the significance of clinical lesions, mites), and infectious agents (e.g., dermatand appropriately use diagnostic tests aids in the diagnosis ophytes, viruses). Knowing whether other animals or people are affected can indicate and management of feline pruritus. Historical Information Signalment

At a Glance Historical Information Page 352

Physical Examination Page 353

Common Diagnostic Differentials for Feline Pruritus Based on Lesion Location

Breed and age at onset of clinical signs provide clues to underlying etiologies. Pruritus in patients younger than 6 months is most commonly caused by parasites (Notoedres, Cheyletiella, and Otodectes spp), allergies (especially ﬂea and food), and dermatophytosis. When pruritus begins in middle age, the differentials are the same, but allergic disease (food allergy, atopic dermatitis) becomes more probable. When pruritus begins in older animals with no history of skin disease, conditions such as epitheliotropic lymphoma, pemphigus foliaceus, Bowen’s disease, and paraneoplastic syndrome should also FIGURE 1

whether a contagious or zoonotic disease is present (e.g., dermatophytosis, cheyletiellosis, scabies). Psychogenic pruritus can be triggered by environmental changes, such as construction, remodeling, moving, or introduction of a new pet or person into the household. Siamese cats and Siamese crosses seem to be at risk for psychogenic disorders; however, psychogenic pruritus should not be assumed based on breed and is diagnosed only after all other causes of pruritus have been excluded.4

Concurrent and Previous Disease In cats with concurrent histories of pruritus and gastrointestinal disease (e.g., inﬂammatory bowel disease), food allergy should be FIGURE 2

Page 353

Diagnostic Tests Page 356

Facial pruritus in a food-allergic Siamese cat.

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Facial and pinnal involvement in a cat with mosquito bite hypersensitivity.

Compendium: Continuing Education for Veterinarians® | August 2009 | CompendiumVet.com

FIGURE 3

TABLE 1

Common Diagnostic Differentials for Feline Pruritus Based on Lesion Location Lesion Location Diagnostic Differentials

Pemphigus foliaceus with secondary bacterial pyoderma around the claw folds in a cat.

Ear canals

Food allergy Atopic dermatitis Notoedres infection Otodectes infection

Head and neck

Food allergy Atopic dermatitis Flea allergy Notoedres infection Mosquito bite hypersensitivity Otodectes infection Viral dermatoses Idiopathic facial dermatitis (“dirty face” syndrome) Drug reaction

diligently investigated. Atopic dermatitis should be strongly considered in pruritic animals with concurrent airway disease or asthma. Viral dermatoses should be suspected in cats with a history of upper airway viral disease and erosive facial lesions. A detailed drug history is critical because certain drugs and vaccines can trigger erythema multiforme and pemphigus foliaceus.5 Nasal planum

Mosquito bite hypersensitivity Viral dermatoses Squamous cell carcinoma Pemphigus foliaceus Cryptococcus infection

Dorsal cervical region

Flea allergy Atopic dermatitis Food allergy Injection-site reaction

Physical Examination Lesion Distribution Observing the distribution of lesions, especially in the initial stages of the underlying disease, can be helpful in narrowing the differential diagnosis. Flea allergy lesions are typically more severe in the lumbosacral, groin, and dorsocervical areas, whereas food allergy lesions are more common on the head. The clinical signs of atopic dermatitis vary but can mimic those of food and ﬂea allergies. Cheyletiellosis lesions (scale, papules, crusts) tend to be distributed dorsally. Dermatophytosis can be localized to a speciﬁc site or can be generalized. Some cats may be asymptomatic carriers of Cheyletiella mites or dermatophytes. Pemphigus foliaceus usually targets the pinnae, bridge of the nose, claw folds (FIGURE 3), and perimammary areas but can also be generalized. TABLE 1 lists some common diagnostic differentials based on lesion distribution.

Lesion Appearance The ability to recognize and identify lesion types can provide valuable information in the evaluation of a pruritic cat. Excoriations, a nonspeciﬁc sign of self-trauma typically associated with pruritus, are characterized by their linear shape and are most prevalent on the head and neck. Erosions are superﬁcial

QuickNotes Observing the distribution of pruritic lesions, especially in the initial stages of the underlying disease, can be very helpful in narrowing the differential diagnosis.

Dorsal and lumbar Flea allergy region Cheyletiellosis Claw folds

Pemphigus foliaceus Bowen’s disease

Ventral abdomen

Demodex gatoi infection Food allergy Atopic dermatitis Flea allergy Psychogenic pruritus

Generalized

Dermatophytosis Food allergy Atopic dermatitis Flea allergy Pemphigus foliaceus Epitheliotropic lymphoma Drug reaction Paraneoplastic syndrome Erythema multiforme

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FIGURE 4

Indolent ulcers in a cat with flea allergy dermatitis.

lesions that are similar to, but often wider than, excoriations. Erosions caused by scratching tend to be linear, whereas those associated with licking tend to be circular. Erosions are often associated with eosinophilic plaques. Ulcers can appear as focal, nonpruritic lesions on the upper lip, known as rodent or indolent ulcers (FIGURE 4). These lesions are one of the components in the eosinophilic granuloma complex (EGC) triad. EGC lesions are reaction patterns that typically indicate an underlying allergy or hypersensitivity reaction, not a specific disease.6 Other conditions that can create skin ulcers with variable degrees of pruritus include vasculitis, autoimmune diseases, drug reactions, and neoplasia. Papules are small (1 to 5 mm), raised lesions that are often associated with crusts and are the most common lesions seen in miliary dermatitis. Like EGC lesions, miliary dermatitis is a sign of an underlying disease. It can be associated with flea allergy dermatitis (most common), atopic dermatitis, food allergy, bacterial folliculitis, cheyletiellosis, dermatophytosis, pemphigus foliaceus, and drug reactions. Plaques appear as moderate to well-defined elevations of the skin with erythema. Eosinophilic plaques, one of the EGC variants, are most commonly associated with underlying allergic disease (FIGURE 5). Eosinophilic granulomas, the third component of the EGC complex, are firm, sometimes ulcerated, raised areas that are often found in the mouth or in a linear pattern on the body (FIGURE 6). Alopecia that is associated with pruritus usually presents as broken off, barbered hairs from overgrooming, scratching, or rubbing. Other lesions of pru-

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FIGURE 5

FIGURE 6

Eosinophilic plaques in a cat with atopic and flea allergy dermatitis.

ritus are often present with alopecia; however, in some cases, broken or barbered hair is the only clue that the cat is pruritic. Thin ﬂakes of shed epidermis characterize scale, a nonspeciﬁc sign that is commonly seen in cheyletiellosis.

QuickNotes Various allergies look the same on histopathology, so biopsy is usually not used to diagnose allergy and is never used to differentiate allergic reactions.

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Diagnostic Tests Cytology/Skin Scrapings Used appropriately, dermatologic diagnostic tests can be powerful tools. Skin scrapings are one of the easiest and most important of these tests and should be conducted for all pruritic cats except those with seasonal signs. Some of the more common parasites that can be identified on skin scraping samples include Cheyletiella blakei, Otodectes cynotis, Lynxacarus radovskyi, Trombicula autumnalis, Felicola subrostratus, Notoedres cati, Demodex cati, and Demodex gatoi. Cytology can be used to assess samples for the presence of bacteria, inflammatory cells, fungal spores and hyphae, acantholytic cells, and neoplastic cells. Cytology should be conducted for any pruritic cat with dermatologic lesions other than noninflammatory alopecia. True pyoderma cases should demonstrate intracellular bacteria, usually within neutrophils and, sometimes, within eosinophils. Eosinophils are inflammatory cells that are common in a variety of disorders, but they are most commonly associated with ectoparasites, allergies, and some forms of EGC lesions. Fungal spores and hyphae are common in cases of dermatophytosis. A fun-

Oral eosinophilic granulomas in a cat with concurrent indolent ulcers.

gal culture should always be performed for speciation. Cytology can also be of value in identifying some forms of cutaneous neoplasia. On rare occasions, it can identify ectoparasites such as Cheyletiella, especially when adhesive tape is used to collect the sample. Acantholytic cells suggest pemphigus foliaceus, although they can also be seen in dermatophytosis. Using a ﬁne-tooth comb on the entire haircoat for several minutes to collect dander and scale for microscopic examination is considered the most reliable method to ﬁnd Cheyletiella mites in both symptomatic and asymptomatic animals.7

Fungal Culture Fungal culture using dermatophyte test medium (DTM) is considered the gold standard for identifying dermatophytes. Dermatophyte infections can present as pruritic infections with any lesion type. When cultured on DTM, dermatophytes produce an alkaline by-product that changes the color of the medium from yellow to red. However, saprophytic contaminants may also turn the medium red under certain conditions. Therefore, DTM should be inspected daily for color change, and any growth must be examined microscopically for evidence of microconidia and macroconidia. Suspected fungal growth can be lifted with clear adhesive tape, stained with lactophenol cotton blue, and examined microscopically. Speciation of the dermatophytes should always be performed to determine the source of infection and help prevent future reinfection.

Compendium: Continuing Education for Veterinarians® | August 2009 | CompendiumVet.com

Hair Examination use this product daily to every other day for the Hair examination using a Wood lamp can be 4- to 6-week period.9 However, this method can helpful in suspected cases of dermatophytosis, be expensive and is difficult in cats that are hard but fluorescence is seen in only a small percent- to pill. Another option is to use a topical formuage of cases of Microsporum canis infection. lation of a flea control product that is approved Hairs that fluoresce should be plucked for cul- for cats every 2 weeks for a 4- to 6-week period. ture for definitive diagnosis.1 Direct microscopic Some of these products are labeled for more freexamination of the hair can also identify der- quent than monthly application. matophytosis. Hyphae and spores can often be seen when the condenser lens is turned down, Food Elimination Trials although culture should always be performed When evaluating a cat for food allergy derto confirm the diagnosis. In cases of alopecia matitis, a food elimination trial must be conin which the degree of pruritus is unknown, ducted, as serologic testing is unreliable and conducting trichograms to examine the tips of inaccurate in domestic animals.10 Food-allergic plucked hairs can help determine if the alopecia cats can have the same clinical signs as aniis caused by self-trauma, in which case, the hair mals with atopic dermatitis or flea allergy, but they commonly present with severe pruritus tips appear fractured and jagged. of the head and neck. The only way to diagSkin Biopsy nose food allergy is to feed an elimination diet Skin biopsy can be a powerful tool when used for an 8- to 12-week period. I prefer a trial appropriately. Many specific infectious, para- consisting of a home-cooked diet or a novel sitic, autoimmune, and neoplastic diseases can limited protein–based commercial diet. I typibe diagnosed using biopsy. Biopsy is indi- cally only use a hydrolyzed diet if the other cated for unusual lesions or clinical presen- diets are not eaten. Owners who are willing to tations or when a case does not respond to make a home-cooked diet can be directed to standard treatment. However, samples taken balanceit.com, where they can purchase recifrom lesions of allergic disease look the same pes and supplements, or should contact a veton histopathology, so biopsy is not usually erinary nutritionist for a consultation. Because used to diagnose allergies and is never used cats have unique nutritional needs, it is imperto differentiate them. ative that home-cooked diets be balanced, as feeding an unsupplemented diet for more than Flea Control Trials 4 weeks can lead to nutritional deficiencies.11 If all nonallergic differentials have been ruled At the end of the 8- to 12-week trial period, the out, a systematic approach to allergies must be cat is rechallenged with the original diet and pursued. Atopic dermatitis, flea allergy, and food observed for exacerbation of clinical signs. allergy can look identical. Flea allergy is the most common allergy in cats in flea-endemic Allergy Testing locations, and flea control trials should be con- The diagnosis of atopic dermatitis is made primarily on the history and physical findings after ducted to eliminate this differential.8 The goal of a flea control trial is to keep the ruling out all other pruritic diseases. Once atopic cat free of fleas, optimally for 4 to 6 weeks, and dermatitis is diagnosed, allergy testing is used evaluate the degree of subsequent resolution of to determine the specific allergens to which the pruritus. If the environmental flea burden is high, patient is sensitive, typically to start immunothe first step should be to suggest that the owner therapy. Intradermal skin testing, although conconsult an exterminator about treating the indoor sidered the gold standard of allergy testing, is and outdoor environments. The option of keeping difficult to conduct in cats. Feline skin is thinner the cat exclusively indoors during the flea control than canine skin, making intradermal injections trial should always be discussed, although it is harder to perform.12 Furthermore, the degree not always feasible. Because studies in cats have of reactivity at the injection sites is often flatfound oral nitenpyram to have 100% efficacy ter, producing false-negative results.12 In vitro against adult Ctenocephalides felis fleas within allergy tests are available and provide a reason3 hours, an ideal method of performing a flea able alternative to skin testing. Some specialists control trial, especially in outdoor animals, is to prefer this method of allergy testing in cats.

QuickNotes If a diagnosis of atopic dermatitis is made, allergy testing is used to determine the speciﬁc allergens to which the patient is sensitive, typically to start immunotherapy.

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Conclusion Pruritus in cats can be difﬁcult and frustrating to treat. However, with a methodic approach and appropriate diagnostic tests, practitioners can signiﬁcantly decrease the severity of pruritus and improve the quality of life for most cats without chronic use of long-term repository steroids.

TO LEARN MORE

For a more detailed discussion of flea allergy dermatitis, see the May 2009 Applied Dermatology article, “Overview of Flea Allergy Dermatitis,” on CompendiumVet.com.

References 1. Scott DW, Miller WH, Griffin CE. Fungal skin diseases. In: Scott DW, Miller WH, Griffin CE, eds. Muller & Kirk’s Small Animal Dermatology. 6th ed. Philadelphia: WB Saunders; 2001:336-442. 2. Carlotti DN, Remy I, Prost C. Food allergy in dogs and cats: a review and report of 43 cases. Vet Dermatol 1990;1:55. 3. Rosser EJ. Food allergy in the cat. A prospective study of 13 cats. In: Ihrke PJ, Mason IS, White SD, eds. Advances in Veterinary Dermatology II. New York: Pergamon Press; 1993:33. 4. Waisglass SE, Landsberg GM, Yager JA, Hall JA. Underlying medical conditions in cats with presumptive psychogenic alopecia. JAVMA 2006;228(11):1705-1709. 5. Scott DW, Miller WH, Griffin CE. Immune-mediated disorders. In: Scott DW, Miller WH, Griffin CE, eds. Muller & Kirk’s Small Animal Dermatology. 6th ed. Philadelphia: WB Saunders; 2001:667-779. 6. Scott DW, Miller WH, Griffin CE. Miscellaneous skin diseases. In: Scott DW, Miller WH, Griffin CE, eds. Muller & Kirk’s Small Animal Dermatology. 6th ed. Philadelphia: WB Saunders; 2001:1125-1183. 7. Moriello KA. Cheyletiellosis. In: Griffin CE, Kwochka KA, Mac-

Donald JM, eds. Current Veterinary Dermatology: The Science and Art of Therapy. St Louis: Mosby; 1993:90-95. 8. Scott DW, Miller WH, Griffin CE. Skin immune system and allergic skin diseases. In: Scott DW, Miller WH, Griffin CE, eds. Muller & Kirk’s Small Animal Dermatology. 6th ed. Philadelphia: WB Saunders; 2001:543-666. 9. Schenker R. Tinembart O, Humbert-Droz E, et al. Comparative speed of kill between nitenpyram, fipronil, imidacloprid, selamectin and cythioate against adult flea Ctenocephalides felis (Bouche) on cats and dogs. Vet Parasitol 2003;112:249-254. 10. Jeffers JG, Shanley KJ, Meyer EK. Diagnostic testing of dogs for food hypersensitivity. JAVMA 1991;198(2):245-250. 11. Mueller RS, Jackson H. Atopy and adverse food reaction. In: Foster AP, Foil CS, eds. BSAVA Manual of Small Animal Dermatology. 2nd ed. Gloucester, England: BSAVA; 2003:125-136. 12. Gilbert S. Feline pruritus therapy. In: Bonagura JD, Twedt DC, eds. Kirk’s Current Veterinary Therapy. 14th ed. St. Louis: Saunders Elsevier; 2009:405-410.

Research Recap Selected abstract from Veterinary Therapeutics

Effect of Intraarticular Injection of Autologous Adipose-Derived Mesenchymal Stem and Regenerative Cells on Clinical Signs of Chronic Osteoarthritis of the Elbow Joint in Dogs* Black LL, Gaynor J, Adams C, et al. Vet Ther 2008;9(3):192-200. Autologous adipose-derived mesenchymal stem cell (AD-MSC) therapy involves harvesting fat from the patient, isolating the stem and regenerative cells, and administering the cells back to the patient. Autologous AD-MSC therapy in veterinary regenerative medicine has been commercially available since 2003. Previously reported results from a blinded, controlled trial in dogs with chronic osteoarthritis of the coxofemoral (hip) joint demonstrated efﬁcacy of a single intraarticular injection of autologous AD-MSC therapy. The primary objective of the current study was to evaluate the effectiveness of this therapy in

dogs with chronic osteoarthritis of the humeroradial (elbow) joints and to determine the duration of effect. Fourteen dogs were recruited. Veterinarians assessed each dog for lameness, pain on manipulation, From the range of motion, and functional disability Fall 2008 issue using a numeric rating scale at baseline and speciﬁed intervals up to 180 days after treatment. Statistically sigTO niﬁcant improveLEARN ment in outcome MORE measures was For more Veterinary Therapeutics abstracts, visit the archives at demonstrated.

VeterinaryTherapeutics.com *This study was sponsored by Vet-Stem, Inc. Poway, California.

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SERIES EDITOR Craig E. Grifﬁn, DVM, DACVD Animal Dermatology Clinic, San Diego, California

SERIES EDITOR Wayne S. Rosenkrantz, DVM, DACVD Animal Dermatology Clinic, Tustin, California

Otitis: Anatomy Every Practitioner Should Know ❯❯ Craig E. Grifﬁn, DVM, DACVDa Animal Dermatology Clinic San Diego, California

hronic otitis externa is a difficult, frustrating problem. ear, which are enclosed by bones of the skull. Four etiologic components must be considered: primary Some giant-breed dogs have ear canals up to 11 cm long. More detailed descriptions of and secondary causes and perpetuating and predisposing the ear canal are given elsewhere.2 The tymfactors.1 Usually, these cases are complex and involve more panic membrane and medial end of the ear than one component. Perpetuating factors are changes in the canal are located ventral and caudal to, but anatomy and physiology of the ear that occur in response to almost on the same medial-to-lateral plane as, the eye (FIGURE 2). The most important anainflammation in the ear canal and the perpetuating factors tomic structures with regard to otitis are the already present. They are self-perpetuating, are not disease external ear canal, tympanic membrane, and specific, and include failure of self-cleaning mechanisms and middle ear. proliferative changes that create folds and stenosis of the External Ear lumen of the ear canal. Elimination of perpetuating factors The external ear is formed from two pieces of often requires aggressive cleaning of the ear and long-term cartilage and a bony canal that are covered by therapy. It is important to avoid damaging key structures skin. It ends medially at the thin tympanic membrane. The epithelium of the ear canal is conwhile aggressively cleaning the ear. Therefore, to adequately tinuous with the epithelium of the lateral aspect diagnose and manage perpetuating factors, veterinarians of the tympanic membrane so that the complete must recognize normal ear anatomy and physiology. FIGURE 1

Anatomy

At a Glance Anatomy Page 504

Physiology Page 510

aDr.

Griffin discloses that he has financial relationships with Efficas, Intervet/Schering-Plough Animal Health, Novartis Animal Health, Pfizer Animal Health, Sogeval, and Teva Animal Health.

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The ear (auris) is the vestibulocochlear organ. It is divided into three major portions: external, middle, and inner (FIGURE 1). The external ear consists of the pinna (auricle) and ear canal (external acoustic meatus). The shape of the pinna varies widely among breeds. For the purpose of describing anatomy, this article considers the erect-eared pinna (as seen on German shepherds) as it projects dorsally and laterally, with its concave surface facing rostrally. Numerous muscle attachments allow the pinna to move and thereby improve its function of helping collect sound waves. The sound waves enter the ear as they pass through the external oriﬁce of the ear canal, located at the base of the pinna. The ear canal, which can be 5 to 10 cm in length, travels to the tympanic membrane and middle

Illustration showing a cross-section of the ear and its major components. With permission from Pfizer Atlas of Infection in Dogs and Cats. Wilmington, DE: The Gloyd Group, Inc; 2008.

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FIGURE 2

FIGURE 3 Straightening the pinna to perform the ear examination.a

QuickNotes

The auricular projection before the pinna is straightened.

Illustration of the relative locations of the ear canal and middle ear. With permission from Pfizer Atlas of Infection in Dogs and Cats. Wilmington, DE: The Gloyd Group, Inc; 2008.

ear canal is lined with epithelium. The larger portion of cartilage (the auricular cartilage) forms the pinna and most of the ear canal. The pinna rolls onto itself at the external oriﬁce of the external ear canal (FIGURE 1). From the external oriﬁce, the canal travels ventrally and slightly rostrally. This is the vertical canal. In the vertical canal, a projection of auricular cartilage emerges from the medial surface under the skin. This projection is unnamed, and its size varies between breeds and between individuals of the same breed. However, it is recognizable when examining the ear with an otoscope because it creates a “corner” around which the examiner must proceed to gain access to the canal. To prevent the auricular projection from blocking access to the ear canal lumen during otoscopic examination, pull the pinna dorsally and laterally. The tension created partially reduces the projection and straightens the ear canal lumen, allowing better access with the otoscope (FIGURE 3). At its ventral end, the ear canal bends

Aggressive cleaning is often needed to manage perpetuating factors, but care must be taken to avoid damaging key anatomic structures.

View of the ear canal after the pinna has been straightened. Note the auricular projection at top left. a

All photographs are copyright of Craig E. Grifﬁn.

medially and continues until it reaches the tympanic membrane. This section, from the bend to the tympanic membrane, is the horizontal ear canal. The skin of the horizontal canal is surrounded by cartilage: the auricular cartilage surrounds the lateral portion, while the smaller anular cartilage, which extends between the auricular cartilage and the external portion of the bone of the external acoustic

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FIGURE 4

FIGURE 5

The anular cartilage (blue arrows) is overlapped by the distal end of the auricular cartilage (white arrows). Note how the anular cartilage overlaps or inserts within the bone of the external acoustic meatus (green arrows).

QuickNotes

FIGURE 6

When otitis is present, the skin covering the auricular projection is often inﬂamed. The pressure of an otoscope cone, especially the edge of the cone, may result in pain and resistance to examination.

A normal canine medial horizontal canal, ending at the tympanic membrane. Note the tuft of hairs (white arrow) adjacent to the ventral portion of the tympanic membrane. The blue arrow is on a dilated, distended pars flaccida with its prominent vasculature. Note the manubrium of the malleus (A) and the pars tensa (B).

VIDEO

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meatus, surrounds the medial portion (FIGURE 4). The anular cartilage and bony external acoustic meatus overlap so that dorsally, the cartilage lies inside the bone of the oriﬁce, but ventrally, the bone is inside the cartilage. The size of the bony external acoustic meatus varies; in midsize dogs, it is about 1 cm long (FIGURE 5). Unlike the skin lining the cartilaginous canal, the skin lining the acoustic meatus lies on bone and therefore is not subject to

The bony external acoustic meatus of a dog skull. The blue arrowheads point to the ventral wall of the lateral and medial edges. The medial arrowhead is where the ventral portion of the pars tensa of the tympanic membrane would attach. The blue line indicates the portion of the horizontal canal where the skin would lie over bone rather than cartilage.

movement and massage. The change from cartilage to bone can be palpated with an angled Buck curette. The medial ring of the acoustic meatus is the location of the tympanic membrane. Often, larger primary hairs grow adjacent to the tympanic membrane (FIGURE 6), commonly on the ventral wall of the lumen. These hairs are a helpful landmark for locating the ventral tympanic membrane when an ear is diseased and the tympanic membrane is not readily apparent.

Tympanic Membrane The tympanic membrane consists of internal and external epithelial surfaces enclosing a thin layer of connective tissue that includes the manubrium of the malleus. It separates the external ear from the middle ear tympanic cavity. The tympanic membrane of the dog is made up of the pars flaccida and pars tensa (FIGURE 7). The pars flaccida, a small area of the dorsal to rostrodorsal aspect, is relatively flaccid and quite vascular. This structure may

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bulge out, can appear cystlike, and can hide the manubrium. Most of what is seen of the tympanic membrane when it is examined through an otoscope is the large pars tensa. A normal pars tensa is translucent, with striations that extend from the manubrium of the malleus out to the periphery. A whitish area with a line or ragged margin can sometimes be seen through the lower to middle section of the pars tensa. This whitish structure is best seen with a strong light source, such as a video otoscope. It represents a structure in the middle ear: the free edge of the septum bulla, which separates the tympanic cavity into dorsolateral and ventromedial parts (FIGURE 7). In dogs, the manubrium of the malleus is C shaped. It is located near the middle of the dorsal part of the pars tensa and points in a rostrocaudal direction. The concave aspect of the C faces rostrally, toward the nose. A perpendicular line from the top of the manubrium would point ventrally. Tension on the manubrium gives the tympanic membrane a mildly concave outer contour.2 The tympanic membrane is oriented at about a 30˚ to 45˚ angle from a dorsal-to-ventral plane. This creates a pocket or groove on the ventral floor of the horizontal canal, adjacent to the tympanic membrane, where small amounts of wax can accumulate. The tympanic membrane moves in response to pressure such as that generated by flushing and cleaning the ear canal. In cats, the tympanic membrane also consists of a pars tensa and pars flaccida, but to date, I have not observed a dilated pars flaccida in a cat. The manubrium of the malleus is relatively larger, is much straighter, and points more rostrally in cats than in dogs (FIGURE 8). In cats and dogs, when myringotomy is performed, the incision should be made in the caudal ventral quadrant of the tympanic membrane (i.e., ventral and caudal to the tip of the manubrium; FIGURE 9).

Middle Ear The middle ear consists of the tympanic cavity and the medial wall of the tympanic membrane; the auditory ossicles and their associated ligaments, muscles, and nerves; and the auditory (eustachian) tube. Normally, the only communication from the middle ear cavity to the outside environment is through the auditory tube, which opens into the nasopharynx and

FIGURE 7

Normal left tympanic membrane with the pars tensa and the vascular pars ﬂaccida. Vessels extend down along the manubrium of the malleus. Note the shadow of the septum bulla (A) seen behind the pars tensa.

serves to equalize pressure on either side of the tympanic membrane. The tympanic cavity may be divided clinically into three parts: dorsal, middle, and ventral. The dorsal part, also called the epitympanic recess, is the smallest and contains the head of the malleus and its articulation with the incus. The middle part, or tympanic cavity proper, is adjacent to the tympanic membrane rostrally and laterally. The prominent structure on the caudal medial aspect of the tympanic cavity proper is the promontory of the petrosal part of the temporal bone (FIGURE 10). The barrel-shaped promontory is situated roughly opposite to the mid-dorsal aspect of the tympanic membrane. At the caudal end of the promontory is the cochlear window, which communicates with the cochlea of the bony labyrinth (FIGURE 11). This structure must be avoided when a myringotomy is performed and the middle ear is ﬂushed. The caudal opening of the auditory tube lies in the rostral-medial part of the middle tympanic cavity. The middle portion of the tympanic cavity communicates freely with the ventral portion, contained in the egg-shaped tympanic bulla. The ventral portion is the largest portion of the tympanic cavity. A ridge of bone, the septum bulla, projects from the medial wall of the tympanic bulla into the cavity between its middle and ventral components. The septum bulla is readily seen just ventral and caudal to the promontory and cochlear window (FIGURE 12) and

QuickNotes In an abnormal ear, tympanic movement is helpful in identifying the tympanic membrane.

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FIGURE 8 Anatomy of the feline middle ear.

Needle A is inserted into the auditory tube. Needle B goes into the tympanic cavity up through a ventral bulla osteotomy opening.

QuickNotes

The needle (A) can be seen in the middle ear. Note that the manubrium (C) is relatively larger than that in the canine ear, and the long axis points rostroventrally, not ventrally as in dogs.

When possible, the middle ear anatomy of cats should be avoided when cleaning.

The needle (B) is inserted through the auditory tube. This view is through the external acoustic meatus.

often has many bony ossicles or “knobbed spicules” along the free edge in the tympanic cavity2 (FIGURE 13). This ridge makes passing catheters or tubes into the ventral bulla very difficult. When the middle ear is flushed, the goal is to direct fluid pressure below the septum bulla. The inner ring of the osseous external acoustic meatus is a helpful landmark because it is the attachment site of the tympanic membrane. If the ventral inner edge can be palpated with an ear loop, then the tympanic membrane is either ruptured or out of

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The needle is pointing from the dorsal portion of the ventral bulla into the ventral portion. Fluid that reaches the ventral portion is trapped by the septum. This ventral-to-dorsal view looks through a hole in the ventral bulla.

its normal anatomic position (FIGURE 14). Once the ventral medial edge of the osseous external acoustic meatus is reached, the cochlear window is a short distance (5 to 8 mm) medially. Care should be taken to stay caudal and ventral to the cochlear window. The middle ear in cats is very different from that in dogs in that the septum bullae is very large and nearly divides the ventral portion of the tympanic cavity into a small dorsolateral and a large ventromedial part—the pars tympanica and pars endotympanica, respectively. These

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FIGURE 9

FIGURE 10

A tomcat catheter in the left external ear canal, pointing to the optimal site for performing a myringotomy. The incision is made in the caudal ventral quadrant of the pars tensa of the tympanic membrane (blue lines). This site is caudal to the convex surface and below the tip of the manubrium.

View through the left external acoustic meatus of a dog skull. An orange feeding tube (A) enters the middle ear from the auditory tube. The septum bulla (B), promontory (P), and opening in the promontory to the cochlear window (C) can be seen.

FIGURE 11 Ventral to dorsal view through an opening in the ventral wall of the bulla of a dog skull. Note the metal rod (A) passing through the lateral margin of the bony external acoustic meatus (B). C indicates the medial edge of the bony external acoustic meatus. The tip of the metal rod (arrow) is through the cochlear window. This site must not be touched or subjected to direct pressure during procedures such as flushing the middle ear.

S indicates the septum bulla.

QuickNotes When the tympanic membrane is ruptured, ear medications and cleansers should be used cautiously and be nonototoxic.

The white lines indicate the lateral ventral edge and medial ventral edge of the bony external acoustic meatus. The distance between the lines varies from 7 to 15 mm and is narrower on the rostral side.

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FIGURE 12

FIGURE 13

Close-up view of the septum bulla showing the bony ossicles (arrows) on the free margin. FIGURE 15 View of the middle ear through the external acoustic meatus. P = promontory, S = septum bulla, C = cochlear window. FIGURE 14

Feline skull showing a needle going through the auditory tube into the tympanic cavity proper. The large, almost complete septum is seen ventral to the manubrium of the malleus.

two parts of the tympanic cavity communicate through a small opening in the caudal medial quadrant near the promontory and cochlear window (FIGURES 15 AND 16). Liquid medications instilled into the feline tympanic cavity are difďŹ cult to remove because they are trapped once they enter the ventromedial portion. View of the left middle ear from the ventral bulla, with an ear loop just over the medial ventral edge of the external acoustic meatus (E). If the tip of the ear loop drops over this edge, it has passed the normal attachment site of the ventral edge of the pars tensa on the tympanic ring. Note the promontory (P) and the cochlear window (C).

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Physiology The skin lining the ear canal is relatively smooth. Similar to the skin in most body regions, it has a thin epidermis and a dermis that contains adnexa (hair follicles and sebaceous and apocrine glands). The vertical canal has relatively more

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adnexa than the horizontal canal. To date, breed differences in the number of sebaceous glands have not been shown, although apocrine gland and hair follicle densities differ.3 The skin and adnexa constantly produce exfoliating corneocytes, intercellular material, and glandular secretions. This material forms cerumen (earwax), which is thought to play a protective role. IgA, IgG, and IgM have been identified in canine cerumen.4 IgG is the predominant immunoglobulin in both normal and inflamed ears. Its relative concentration increases significantly in the presence of disease. Cerumen also contains a wide variety of lipids, which may have some antimicrobial effects5; however, bacteria and yeast are present in normal ears. Cerumen is constantly being produced throughout the ear canal, and if it were to build up, blockage could result. However, there is a normal clearing mechanism: the movement of the epidermis. Epithelial migration, in which the surface of the skin lining the ear canal constantly moves from the tympanic membrane laterally to the external orifice of the ear canal (FIGURE 17),

FIGURE 16

Close-up photo of a feline middle ear viewed through the external acoustic meatus. Note the opening (O) in the septum that communicates with the larger ventromedial part of the tympanic cavity, the endotympanic part of the temporal bone. C = cochlear window, P = promontory.

has been shown in humans and guinea pigs.6 It seems likely that besides removing the cerumen, this process also facilitates the removal of sur-

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FIGURE 17 Illustrations depicting the migration of cerumen and surface epithelial cells from the deep ear canal to the external oriﬁce.

This process must function for an ear canal to remain healthy. With permission from Pfizer Atlas of Infection in Dogs and Cats. Wilmington, DE: The Gloyd Group, Inc; 2008.

face microorganisms and even small particulate dog and cat ears at 1000× magnification,1 I debris trapped in the sticky cerumen. consider bacteria excessive when more than Cytologic studies of normal ear cerumen five cocci or one rod per 1000× (oil immerhave produced variable results in numbers of sion) field is found. Normal numbers of yeast bacteria and yeast but have found essentially are even more controversial, although I conno inflammatory cells.7,8 These studies evalu- sider more than three organisms in dogs or ated samples at 400× dry field magnification, more than one in cats per oil immersion field not by oil immersion (1000×), which is my pre- to be increased. Rarely, up to 20 organisms per ferred magnification. It has been stated that 1000× field can be normal for an individual dog 400× magnification is not sufficient to identify or cat. However, these numbers are irrelevant all bacteria.9 Based on a published, non–peer- once multiple inflammatory cells are present, reviewed evaluation of cerumen from normal as this finding is abnormal. References 1. Scott DW, Miller WH Jr, Griffin CE. Muller and Kirk’s Small Animal Dermatology. 6th ed. Philadelphia: WB Saunders; 2001. 2. Evans H. Miller’s Anatomy of the Dog. 3rd ed. Philadelphia: WB Saunders; 1993. 3. Stout-Graham M, Kainer RA, Whaler LR, Macy DW. Morphologic measurements of the external horizontal ear canal of dogs. Am J Vet Res 1990;51(7):990-994. 4. Huang HP, Little CJ, Fixter LM. Effects of fatty acids on the growth and composition of Malassezia pachydermatis and their relevance to canine otitis externa. Res Vet Sci 1993;55(1):119-123. 5. Huang HP, Fixter LM, Little CJ. Lipid content of cerumen from

normal dogs and otitic canine ears. Vet Rec 1994;134(15):380-381. 6. Johnson A, Hawke M. An ink impregnation study of the migratory skin in the external auditory canal of the guinea-pig. Acta Otolaryngol 1986;101(3-4):269-277. 7. Ginel PJ, Lucena R, Rodriguez JC, Ortega J. A semiquantitative cytological evaluation of normal and pathological samples from the external ear canal of dogs and cats. Vet Derm 2002;13(3):151-156. 8. Tater K, Scott DW, Miller WH Jr, Erb HN. The cytology of the external ear canal in the normal dog and cat. J Vet Med 2003;50:370-374. 9. Angus JC. Otic cytology in health and disease. Vet Clin North Am Small Anim Pract 2004;34(2):411-424.

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Successful Use of Probiotics in a Dog with Chronic Diarrhea Teresa A. Bessler, DVM Buffalo Veterinary Clinic Buffalo, Wyoming

Patient: Kodi, a 14-year-old American Eskimo dog History: When Kodi became my patient in August 2007, he had a 2-year history of kidney disease and was eating Purina Veterinary Diets® NF Kidney Function® canine formula to help manage his condition. He also had a long history of frequent bouts of watery diarrhea. Therapy Plan: Because of Kodi’s chronic kidney disease, I instructed the owners to continue feeding NF. I also prescribed 1 g of sucralfate twice daily for 5 days to treat a brief episode of anorexia and 250 mg of metronidazole twice daily for 5 days to resolve the diarrhea; metronidazole helped briefly, but the diarrhea returned. In October 2007, Kodi’s owners made an appointment to have him euthanized because of the chronic diarrhea. Kodi was having fecal accidents in the house, and the owners did not wish to pursue expensive diagnostics. I talked to them about Purina Veterinary Diets® FortiFlora® Canine Nutritional Supplement, and they agreed to try it. Kodi was given FortiFlora once daily, and Purina Veterinary Diets ® Gentle Snackers TM were allowed as treats. Outcome: Two weeks after adding FortiFlora to the diet, Kodi’s diarrhea had transformed into fairly firm stools. FortiFlora helped resolve the problem. At Kodi’s last evaluation, the chronic diarrhea hadn’t returned. This information has not been peer reviewed and does not necessarily reflect the opinions of, nor constitute or imply endorsement or recommendation by, the Publisher or Editorial Board. The Publisher is not responsible for any data, opinions, or statements provided herein.

Veterinarian’s Comments I have been recommending Purina Veterinary Diets® FortiFlora® as a nutritional supplement for the past 2 years. I find it to be very effective in cases of acute and chronic diarrhea and in patients on long-term antibiotic therapy. I estimate that I have used FortiFlora in at least 40 patients with a 90% success rate. I explain to owners that FortiFlora is a nutritional supplement that contains beneficial bacteria and promotes intestinal health. Owners appreciate that FortiFlora comes in premeasured packages and is simply sprinkled on top of the pet’s food. FortiFlora delivers good clinical results, and dogs and cats find it palatable; I have not had one owner tell me that his or her pet would not eat it. Kodi’s owners were very happy with the positive results obtained with FortiFlora. They told me the nutritional supplement had changed their lives and Kodi’s as well, and they wished they had known about FortiFlora sooner. Sponsored by

2008 Feline Retrovirus Management Guidelines* Members of the Advisory Panel ❯❯ Julie Levy, DVM, PhD, DACVIM, Chair ❯❯ Cynda Crawford, DVM, PhD University of Florida

❯❯ Katrin Hartmann, Dr. Med. Vet., Dr. Habil., DECVIN-CA Ludwig Maximilian University Munich | Munich, Germany

❯❯ Regina Hoffmann-Lehmann, Dr. Med. Vet., Dr. Habil, FVH University of Zurich | Zurich, Switzerland

❯❯ Susan Little, DVM, DABVP (Feline Practice)

Winn Feline Foundation | Manasquan, New Jersey

❯❯ Eliza Sundahl, DVM, DABVP (Feline Practice)

eLV and FIV are among the most common infectious diseases of cats. Risk factors for infection include male gender, adulthood, and outdoor access, whereas indoor lifestyle and sterilization are associated with reduced infection rates.1–5 The retroviral status of all cats should be known. Cats may require retrovirus testing at different times in their lives. Here are some general principles for retrovirus testing:

A cat with a confirmed-positive test result should be diagnosed as having a retroviral infection—not clinical disease. Diseases in cats infected with FeLV or FIV may not necessarily be the result of the retrovirus infection. Cats infected with FeLV or FIV may live for many years. A decision for euthanasia should never be made solely on the basis of whether the cat is infected. No test is 100% accurate at all times under all conditions. All test results should be interpreted along with the patient’s health and prior likelihood of infection. All positive results should be confirmed by another test method.

While FeLV and FIV can be life-threatening viruses, proper management can give infected cats longer, healthier lives. The following article reflects the recommendations of the AAFP on managing these infections.

KC Cat Clinic | Kansas City, Missouri

❯❯ Vicki Thayer, DVM, DABVP (Feline Practice) Purrfect Practice | Lebanon, Oregon

At a Glance Epidemiology Page 265

Preventing FeLV and FIV Infection Page 265

Limiting Transmission in the Veterinary Practice Page 268

Diagnosing FeLV and FIV Page 269

Managing Positive Cats

About These Guidelines This report represents a consensus of current information compiled by the researchers and practitioners on the panel. These guidelines are based on the best research data, clinical experience and technical judgments available at the time of preparation. While the guidelines are as accurate and comprehensive as possible, they are subject to change should new insights become available from additional research or technological updates. The American Association of Feline Practitioners is a professional organization of practitioners and board-certified specialists who seek to raise the standards of feline medicine and surgery among practitioners.

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* This is an abridged version of the full guidelines (Levy JC, Crawford C, Hartmann K, et al. 2008 American Association of Feline Practitioners’ feline retrovirus management guidelines. J Feline Med Surg 2008;10[3]:300-316) available at catvets.com from the American Association of Feline Practitioners (AAFP). Adapted with permission from AAFP.

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the home page for veterinary professionals CE ARTICLES HANDOUT ❯❯ What You Need to Know About Feline Upper Airway Infections

ns ons your cat Airway Infectio r what vaccinati have been can remembe like the your cat might your cat. And, just has had, when cat, and when an infected an infected Some litterbox as can play a role exposed to of being sick. your hands show signs help common cold, so if you have cat began to necessar y to g these viruses, tests may be hands before in spreadin laborator y cat, wash your ss. or touch a sick h the diagnosi with cat! touching another are no longer sick, many ite they herafter Even with feline lose their appet been infected s Many sick cats cats that have transmit these stion affect calicivirus can conge seek profesnasal e, pesvirus and because cats. Therefor a these cats introducing viruses to other of smell, so y advice before history the sense their sional veterinar with baby n vaccination an unknow e tempted with your cat in new cat with ne to be may need treat or before placing us treat. err delicious into your house her anot anoth or setting ar food an unfamili facility. trol a boarding

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Cats, especially kittens, often get upper airway infections. This handout provides information about feline upper airway infections and offers suggestions and solutions to cat owners for preventing and treating these infections. The handout can be found on pages 579–580 or can be downloaded from Vetlearn.com.

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❯❯ Perfusion Versus Hydration: Impact on the Fluid Therapy Plan ❯❯ Caroline C. Tonozzi, Elke Rudloff, and Rebecca Kirby Creating a fluid therapy plan adequate to meet an individual patient’s needs depends on identifying whether the animal has poor perfusion, is dehydrated, or both. This article reviews the body’s fluid compartments, fluid dynamics, and the clinical parameters used to differentiate perfusion from hydration and create a fluid therapy plan.

VIDEOS ❯❯ Ear Anatomy Videos The November Applied Dermatology article, “Otitis: Anatomy Every Practitioner Should Know,” by Dr. Craig E. Griffin, addresses ear cleaning and identifying different structures of the canine and feline ear. Dr. Griffin has submitted five videos to correspond with his article. Topics include otoscopy of the ear canal, movement of the tympanic membrane in response to water pressure, and a demonstration of the massage point at the base of the ear (which can be used with an ear cleaning handout available online).

❯❯ Avian Transfusion Medicine ❯❯ Shannon Shaw, Tom Tully, and Javier Nevarez Anemia is deﬁned as a decreased capacity of the blood to carry oxygen and is recognized by packed cell volume, erythrocyte, and hemoglobin values below reference ranges. Causes of anemia in birds include blood loss, heavy metal toxicosis, parasitic infection, and chronic disease. Several differences exist between avian and mammalian physiology, including the avian ability to tolerate greater losses of blood. However, the use of blood products has become an effective tool for treating anemic avian patients. Whole blood transfusions (autologous, homologous, and heterologous) and administration of hemoglobinbased, oxygen-carrying solutions are the treatments used most commonly in birds. NEWS BITE

Did You Know? Internet Popularity Among Pet Owners a Big Plus The Internet is, by Packaged Facts’ estimates, the fastest growing sales venue for pet products in the United States, with sales expected to surpass $1 billion by 2012, based on more marketers and retailers using the medium as well as the above-average likelihood of pet owners to shop via the Internet and rely on it for information. This is especially good news for “info-centric” health products, which are already heavily represented on the Internet, reﬂecting the grass-roots origins of many such products as well as the ability of the Internet to communicate product beneﬁts with detailed information. The Internet is also important because it hosts a virtual community of pet devotees who exchange pet product ideas and product tips through Web sites, chat groups, blogs, and e-mail.

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Regulation Pet Foods of

❯❯ David A. Dzanis, DVM, PhD, DACVNa Dzanis Consulting & Collaborations

Santa Clarita, California

in the United States

Abstract: In the United States, pet foods (including treats, edible chews, and supplements) are subject to regulation at both federal and state levels. Products found to be adulterated or misbranded are subject to enforcement action. Veterinarians play a key role in helping ensure pet food safety by reporting possible adverse effects to authorities in a timely manner.

n 2007, the widely reported recall of dog and cat foods due to contamination with melamine and related compounds brought renewed public scrutiny of the pet food industry. The Internet is replete with sites that disparage the nutritive value and safety of commercial pet food products, often implicating poor regulatory oversight. Because pet owners often consult veterinarians on matters relating to pet food, it behooves practitioners to be familiar with the topic of pet food regulation.

Who Regulates Pet Foods?

At a Glance Who Regulates Pet Foods? Page 324

Government Oversight of Pet Foods Page 326

Oversight of Veterinary-Dispensed Products Page 326

The Veterinarian’s Role Page 327

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The US Department of Agriculture oversees meat and poultry products intended for human consumption; however, the same products, intended for animal consumption, fall within the authority of the US Food and Drug Administration (FDA). FDA’s Center for Veterinary Medicine has primary jurisdiction over all animal feed in interstate commerce (including imports).1 “Animal feed” includes pet food, which further encompasses complete and balanced foods, treats and snacks, supplements, edible chews (e.g., rawhides, bones), and the ingredients intended to be incorporated into these products. “Interstate commerce” of a product is determined by the Dr. Dzanis is a consultant for the pet food and related industries on matters pertaining to nutrition, labeling, and regulation. He formerly served as the veterinary nutritionist for the US Food and Drug Administration and represented the agency on the Association of American Feed Control Officials Pet Food Committee.

origins of its ingredients, the location where the product was manufactured, and the point of sale or receipt of the product. Most pet foods contain at least some ingredients obtained from sources outside of the state where they are manufactured; therefore, virtually all pet foods fall under federal authority. Individual state governments also exercise authority over animal feed and pet food distributed within their jurisdiction. This constitutes another layer of regulatory oversight that is more extensive than is required for most human food items. Each state’s laws and regulations are enforced by the state feed control official, typically an employee in the state’s department of agriculture or chemist’s office. While the acronym AAFCO commonly appears on “complete and balanced” dog and cat food labels, few in the public understand the nature and role of the Association of American Feed Control Officials (AAFCO) in pet food regulation. AAFCO is neither a government body empowered to act under authority of law nor a trade association whose goal (as ascribed by its critics) is to mitigate the impact of regulation on industry. Rather, it is a private body wholly comprised of federal, state, and foreign gov-

Compendium: Continuing Education for Veterinarians® | July 2009 | CompendiumVet.com

Contributed by The American College of Veterinary Nutrition About ACVN ernment officials.2 Essentially, its role is to provide a Model Bill and Regulations, establish ingredient definitions, and set other standards (such as guidelines for use of the term natural and the AAFCO Dog and Cat Nutrient Profiles and feeding trial protocols), via policy or guidance, that represent a consensus among regulators about what constitutes the appropriate regulation of animal feed. Nothing AAFCO publishes has any power of law unless subsequently adopted by individual state legislatures, and not all states follow AAFCO models. However, enough do that AAFCO has nationwide influence.

Representatives of industry and consumer groups can provide information to committees and working groups within AAFCO and are free to voice their opinions at public AAFCO meetings. However, they are not allowed to be members of AAFCO and hence, cannot hold office, make motions, or cast votes on any matter under consideration.

Founded in 1988, the primary objective of the American College of Veterinary Nutrition (ACVN) is to advance the specialty area of veterinary nutrition and increase the competence of those who practice in this field by establishing requirements for certification in veterinary nutrition, encouraging continuing professional education, promoting research, and enhancing the dissemination of new knowledge of veterinary nutrition through didactic teaching and postgraduate programs. For more information, contact: American College of Veterinary Nutrition, c/o Dawn Cauthen, Administrative Assistant, School of Veterinary Medicine: Dept. of Molecular Biosciences One Shields Avenue Davis, California 95616-8741 Telephone: 530-752-1059 Fax: 530-752-4698 Email: dawncauthen@yahoo.com Web: acvn.org

CompendiumVet.com | July 2009 | Compendium

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QuickNotes State feed control officials often inspect pet stores and other retail outlets that sell pet foods, including veterinary clinics.

326

Government Oversight of Pet Foods With regard to pet food, the federal and state governments’ mandate is to enforce pertinent laws relating to pet food manufacture and distribution. This includes products sold through retail outlets, veterinary clinics, catalogs, and Web sites. The Federal Food, Drug, and Cosmetic Act of 1938 (FFDCA) and equivalent state laws prohibit the distribution of foods that are either adulterated or misbranded.3 The term adulterated may refer to the presence of a chemical, microbiologic, or physical contaminant, including any substance that is not generally recognized as safe, an approved food additive, or an otherwise sanctioned ingredient (e.g., via the AAFCO Feed Ingredient Definition process) for use in pet foods. Failure of a product to meet stated nutrient guarantees or conform to ingredient or nutritional representations is also a form of adulteration.2 The term misbranded relates to false or misleading claims and to labeling that is not in compliance with federal or state regulations. “Drug claims,” which are defined as claims that a product can (1) treat, prevent, mitigate, or otherwise affect a disease or condition or (2) affect the structure or function of the body in a manner beyond what is normally ascribed to food, for which the product is not approved, can be considered a form of misbranding.1 Most enforcement efforts are conducted by state feed control officials. This is because many state laws (particularly those that follow AAFCO models) mandate periodic (usually annual) product registration and/or company licensure as a condition of distributing in the state.2 Typically, the process requires submission of product labels for review by the feed control official. Sale of any product found to be misbranded may be denied in that state, affecting not only distribution of the product within the state, but also deliveries from outside the state based on catalog or online sales. While this action would appear to affect only one jurisdiction, in practice, it is infeasible for pet food companies to distribute products in different states with different labels. Hence, labeling found to be objectionable by one state may result in revision of the labeling for nationwide sale of a product. In addition to their registration/licensure functions, state feed control officials often inspect pet stores and other retail outlets that

sell pet foods, including veterinary clinics. Wholesale distribution points within the state are also subject to inspection. Inspectors may search for products that are not properly registered or have been previously denied sale. Samples of products may be obtained from the location for label review and/or laboratory analysis for nutrient content and contamination. Depending on the egregiousness of any violations found, the product may be seized by the regulator, or the company may be notified and allowed time to remedy the violation. Compared with individual states, FDA conducts little direct enforcement. While FDA can seize product or take other enforcement measures, there are no federal product registration or company licensure requirements at this time (except registration of food manufacturing facilities under the Bioterrorism Act). However, FDA is intimately involved in the process of state enforcement efforts, assisting states with scientific, technical, and regulatory expertise in support of contemplated enforcement actions. For example, feed control officials often refer questionable claims or ingredients to FDA for assessment before taking action, or they may require a company to first obtain FDA’s acceptance as a condition of distribution of its product in their state. Also, FDA has taken direct action when it was deemed more effective than a single state’s action, such as in cases involving catalog and online sales.

Oversight of Veterinary-Dispensed Products Veterinarians frequently dispense therapeutic pet foods as part of normal practice. As noted

Compendium: Continuing Education for Veterinarians® | July 2009 | CompendiumVet.com

above, a pet food label bearing a drug claim is subject to enforcement action. However, FDA often exercises “enforcement discretion” in the case of veterinary therapeutic diets. In other words, it allows companies to convey information to veterinarians on the function of a product as it relates to disease processes, provided that the product is sold under a valid veterinarian/client/patient relationship.4 This discretion is based on the premise that veterinarians’ medical and scientific training is sufficient to enable safe and appropriate use of the product by clients. However, most veterinarians are not aware that the diet/disease claims made by the company most often have not been reviewed and verified by FDA. This is not to imply that such products lack benefit or are unsafe when used as clinically appropriate. On the contrary, manufacturers of therapeutic diets may have extensive documentation. The Veterinary Oral Health Council (VOHC), an organization under the auspices of the American Veterinary Dental College, provides protocols and reviews data from companies with regard to dental plaque and tartar control claims and allows use of its seal of acceptance for products that pass muster in this regard. However, other than VOHC, there are no independent organizations that scrutinize therapeutic diet claims for products sold in the United States. Many veterinarians also distribute pet supplement products to clients. The Dietary Supplement Health and Education Act of 1994 (DSHEA) diminished FDA’s authority over dietary supplements (a subcategory of foods) by allowing the inclusion of ingredients that were previously prohibited in food products as well as broadening the scope of permissible

claims relating to function. This act affects only products that meet the statutory definition of dietary supplements, not foods in “conventional” form. Regardless, FDA has given notice of its determination that DSHEA only applies to products intended for human consumption, so that FFDCA still applies to all pet products, whether in conventional (e.g., a complete and balanced pet food) or supplement (i.e., “dosage”) form.5 In response, some manufacturers of pet supplement products containing unapproved food additives (such as many herbs, botanicals, metabolites, and other compounds) have opted for labeling such products as drugs rather than as foods. While still under the authority of FDA and “animal remedy” laws in some states, products so labeled may escape scrutiny by many state feed control officials. Further, although FDA does allow some products on the market as “unapproved drugs of low regulatory priority” based on its determination of reasonable expectations of safety, it is not obvious by their labeling which products have passed FDA muster in this regard and which have not. As a result, some products on the market may not have received adequate review by regulatory officials.

The Veterinarian’s Role Notwithstanding the adverse attention pet foods have received since the 2007 recall, in general, pet foods have a good safety record.6 Regardless, future contamination incidents are always possible. Clinicians are in an excellent position to detect and report potential pet foodborne illness before a larger outbreak occurs. Suspected or confirmed contamination should be reported to appropriate regulatory agencies (Table 1)

QuickNotes FDA often exercises “enforcement discretion” in the case of veterinary therapeutic diets.

table 1

Reporting Suspected or Confirmed Pet Food Contamination or Adverse Eventsa

Whom to Contact

How to Contact

Alternate Contact Method

Pet food manufacturer

Call “800” telephone number on label.

Visit company Web site.

FDA

Call your FDA district office consumer complaint coordinator. Telephone numbers for district offices are listed at fda.gov/opacom/ backgrounders/complain.html.

Call the telephone number listed in the blue pages (for federal agencies) in the telephone directory.

State feed control official (state agency varies but is usually the department of agriculture or chemist’s office)

Call an AAFCO member in your state. Telephone numbers are listed in the AAFCO membership directory at www.aafco.org/Directory/ MembershipDirectory/tabid/62/Default.aspx.

Call the telephone number listed in the blue pages (for state agencies) in the telephone directory.

Dzanis DA. Anatomy of a recall. Topics Companion Anim Med 2008;23(3):133-136. Reproduced with permission.

CompendiumVet.com | July 2009 | Compendium: Continuing Education for Veterinarians®

327

QuickNotes Veterinarians must practice due diligence in assessing the clinical need for a given supplement in an individual animal.

as well as the manufacturer, which may be in the best position to recognize a pattern of complaints suggesting a safety problem. Pertinent information to relate to regulators and companies includes the product name (including variety) and package size, as well as the universal product code (UPC) number to help identify the exact product in question. Regulators and companies can also use lot or date codes to help pinpoint the production batch(es) of highest concern. The date and place of purchase of the suspect food, as well as relevant medical information regarding the animal, are also helpful. Proper handling of samples of the suspect food as legal evidence may be critical if there is a possibility of a lawsuit at a later date.6 Therapeutic pet foods must meet the same processing, ingredient, and labeling standards as any other pet food, including substantiation of nutritional adequacy. A food labeled “This product is intended for intermittent or supplemental feeding only” should not be considered sufficient for long-term feeding as the sole source of nutrition. In consideration of the lack of regulatory review of efficacy References

1. Benz SA. FDA’s regulation of pet food. Accessed December 2008 at fda.gov/cvm/petfoodflier.html. 2. 2008 AAFCO Official Publication. Oxford, IN: Association of American Feed Control Officials; 2008. 3. Federal Food, Drug, and Cosmetic Act. Washington, DC: Government Printing Office; 1999. 4. Intended use of therapeutic diets as drugs dictates VCPR requirement. JAVMA 2003;222(7):923.

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claims for therapeutic diets, it is prudent for clinicians to carefully scrutinize data supplied by companies in support of the reported benefits of their products. Outcomes of feeding these diets should be closely monitored. Before using or recommending any supplement product, veterinarians must practice due diligence in assessing the clinical need for a given supplement in an individual animal; evaluating the strength, quality, and source of data to support the use of the supplement; and judging the integrity and competence of the manufacturer. Veterinarians must also objectively assess outcomes of supplement administration and be open to revising use or recommendations as necessary. Any observed adverse effects should be reported to the appropriate regulatory officials as well as the manufacturer. Members of the National Animal Supplement Council (NASC)—a trade organization representing the interests of supplement manufacturers—that receive adverse event reports must convey that information to the council to be included in its database.7 NASC allows federal and state regulators, but not the general public, to review this database.

5. Inapplicability of the Dietary Supplement Health and Education Act to Animal Products. Federal Register 1996;61(78):17706-17708. 6. Miller EP, Cullor JS. Food safety. In: Hand MS, Thatcher CD, Remillard RL, Roudebush P, eds. Small Animal Clinical Nutrition. 4th ed. Topeka, KS: Mark Morris Institute; 2000:183-198. 7. National Animal Supplement Council. Frequently asked questions. Accessed December 2008 at: nasc.cc/index.php?option=com_ content&task=view&id=29&Itemid=38.

Compendium: Continuing Education for Veterinarians® | July 2009 | CompendiumVet.com

Service... SevoFlo® (sevoflurane) anesthesia—with expert service, support and training—is smart, efficient and profitable for your practice. Only SevoFlo— available through all major distributors —provides four unique benefits: 1. A minimum of 300 ppm water 2. Shatter-resistant PEN bottles 3. Local Abbott representatives and expert advice 4. Commitment to training and education

You’re probably familiar with SevoFlo. But, do you realize how Abbott Animal Health’s exceptional service and product support helps you, your patients and your practice? SevoFlo and Abbott Animal Health can help your surgical suite run efficiently and profitably. Our team of local representatives provides support and advice. In addition, our technical support department and panel of anesthesiologists are standing by to discuss techniques and equipment. Abbott Animal Health also helps educate you and your staff by providing “lunch-and-learns,” in-clinic training materials and CE sponsorships—we’re committed to the veterinary community. To learn more about SevoFlo, our other anesthetics and our commitment to serving you, contact Abbott Animal Health Customer Service at 888-299-7416 or visit www.abbottanimalhealth.com.

Important Information: How Supplied: SevoFlo is packaged in amber colored bottles containing 250 mL sevoflurane. Indications: SevoFlo is indicated for induction and maintenance of general anesthesia in dogs. Warnings, Precautions, and Contraindications: Like other inhalation anesthetics, sevoflurane is a profound respiratory depressant. Respiration must be monitored closely in the dog and supported when necessary with supplemental oxygen and/or assisted ventilation. Due to sevoflurane’s low solubility in blood, increasing concentration may result in rapid hemodynamic changes compared to other volatile anesthetics. SevoFlo is contraindicated in dogs with a known sensitivity to sevoflurane or other halogenated agents. Adverse Reactions: The most frequently reported adverse reactions during maintenance anesthesia were hypotension, followed by tachypnea, muscle tenseness, excitation, apnea, muscle fasciculations and emesis. See package insert for full prescribing information. See Page 4 for Product Information Summary SEVO-186 June 2008 ©2008 Abbott Laboratories

Using a Diet History to Improve Adherence to Dietary Recommendations ❯❯ Kathryn E. Michel, DVM, MS, DACVN,* University of Pennsylvania Proper dietary management is essential to pet health, yet changing pet owners’ feeding practices is often difficult. Taking a diet history provides an opportunity to open a dialogue about animals’ dietary needs as well as invaluable information that will aid in tailoring specific dietary interventions to the needs and preferences of patients and their caregivers. ommunicating effectively with people the household? Do any of them spend all day about the nutrition and dietary manage- with the pet? Inquire whether there are other ment of their pets can be difficult, par- pets in the home and whether they are—or ticularly when the goal is to persuade them to can be—fed separately from the patient. Can alter their feeding practices. However, circum- the patient get into the other pets’ food? Ask stances frequently arise in which a change in whether the pet is confined indoors or is feeding management may be in the best inter- allowed outside. If the pet is allowed out, is ests of a pet. Obtaining a complete diet history is it supervised while it is outside? Does it have the essential first step in the process of altering the opportunity to steal food, get into garbage, feeding practices to suit a pet’s needs. The diet scavenge, or hunt? history provides information about what the pet is being fed and whether this food is complete, The Principal Diet, Feeding Routines, balanced, and appropriate to the pet’s life stage and Eating Behaviors and health status. Just as important, the history Obtain the precise names (including flavor, if provides information about how food is used appropriate) and brands of all commercial pet in interactions between the pet and the other foods that the patient is receiving and the spemembers of the household. Understanding this cific amounts fed. Often, caregivers cannot prorelationship is a key element when designing vide this information accurately by recall alone dietary interventions that meet the health and and need to check labels and measure feeding nutritional needs of the patient and are accept- portions. Also, pet owners who use a scoop to measure dry food often do not realize the true able to the pet’s caregivers. size of their measuring device. If the pet is eatElements of the Diet History ing a canned diet, ask what size can the owner A complete diet history gives an accurate account buys. Some varieties of pet food are sold in of all foods fed to a pet on a typical day. It is an multiple can sizes (e.g., 5.5 and 12 oz), so the opportunity to evaluate all the ways that food size used by the client is important informais involved in interactions between the pet and tion. Make sure to ask whether the food the pet the other members of its household. It should is currently eating is its usual diet and, if not, also be an opportunity for the pet’s caregivers when the diet change was implemented. to offer their viewpoints regarding the propoIf the pet is eating a commercial pet food, sition of modifying their feeding practices. ask if the diet is being supplemented with any human foods. If this is the case, it is important The Household to get accurate details, including measured Begin by asking about who lives with the amounts of all foods routinely given to the pet. How many adults and children are in pet. If the pet is being fed a home-prepared

QuickNotes Information from the diet history is essential for determining whether a patient is receiving an appropriate and adequate diet.

*Dr. Michel discloses that she has received ﬁnancial support from Nestlé Purina PetCare Company and Royal Canin.

Compendium: Continuing Education for Veterinarians® | January 2009 | CompendiumVet.com

CONTRIBUTED BY THE AMERICAN COLLEGE OF VETERINARY NUTRITION About ACVN diet, ask for the recipe, including measured amounts of all the ingredients. Some owners do not use a standard recipe when making a home-prepared diet. It is useful to ask these owners to keep a diary of all food fed to the pet for 5 to 7 days. Be certain to inquire whether the pet is receiving any dietary supplements. If possible, have the client bring in the supplements—or at least the label information—so you can see exactly which nutrients are being supplemented and in what quantities. Ask about the daily routine of feeding the pet. Is the pet fed at certain times of the day, or is food always available? If the pet is fed with other pets, are the meals supervised? Does one person assume responsibility for feeding the pet, or can it vary day-to-day? This is important information, especially when you are making dietary recommendations, because the person who brings the pet to the ofﬁce may not be the person who will be implementing the new plan. Ask about how and where the food is stored (e.g., in a sealed container, in the refrigerator). If the pet is fed a dry food, is the food bought in large quantities, and how long does it take to use up a bag of food? Food can lose its freshness over time, especially if it is not stored under optimal conditions. Inquire about the pet’s normal feeding behavior. Is the pet an “easy keeper” or a picky eater? Does the pet eat the food as soon as it is offered, or is it content to graze throughout the day? Does the pet usually eat all the food that is offered? Does the pet beg for food between meals? If the pet is not eating as it normally does, ﬁnd out what has changed and for how long the behavior has been altered.

Treats, Supplements, and Exercise When inquiring about treats, ask the question several times in different ways. Ask speciﬁcally about which commercial treats are used—not just the brand name but also the ﬂavor, variety, and size. Ask about human foods and table scraps. Ask about products or foods that are used to promote chewing and dental hygiene or to alleviate boredom. Also inquire about different ways food may be used as a reward, such as for performing tricks or for good behavior during walks. Owners do not always

consider such items treats, and many of the products and foods used for these purposes are high in calories. It is important to remember to inquire whether the pet routinely receives any supplements or medications that are disguised with food. Human foods that are typically used to pill a dog or cat, such as cheese, lunch meats, or peanut butter, are often high in sodium, fat, and calories. For example, one study evaluating dogs with cardiac disease showed that 62% of the owners used human or pet food for pill administration and that many of these foods were high-sodium table foods such as cheese or lunch meats.1 One further point to ask about is the pet’s level of activity and opportunity to exercise. Is the pet walked regularly? How often, and how far? Find out whether the pet goes outside, has a fenced-in yard—and if so, how large— or participates in regular activities that involve exercise, such as going to a dog park or an agility class. See if you can gauge whether increasing the opportunity to exercise would be feasible in the household. This information is especially valuable when you are designing a weight reduction program for a patient.

Founded in 1988, the primary objective of the American College of Veterinary Nutrition (ACVN) is to advance the specialty area of veterinary nutrition and increase the competence of those who practice in this ﬁeld by establishing requirements for certiﬁcation in veterinary nutrition, encouraging continuing professional education, promoting research, and enhancing the dissemination of new knowledge of veterinary nutrition through didactic teaching and postgraduate programs. For more information, contact: American College of Veterinary Nutrition, c/o Dawn Cauthen, Administrative Assistant, School of Veterinary Medicine: Dept. of Molecular Biosciences One Shields Avenue Davis, California 95616-8741 Telephone: 530-752-1059 Fax: 530-752-4698 Email: dawncauthen@yahoo.com Web: acvn.org

Gathering the Information This may seem like a great deal of information to gather in a routine office visit, but the process can be expedited by having a diet history form available for clients to fill out while they are in the waiting room. As previously mentioned, the client may not be able to recall all of the information in the office and may need to take the form home. If your practice has a Web site, you can have a link to a downloadable version of the form so that clients can fill it out before the office visit. To help expedite the WEB EXCLUSIVE process, a veterinary technician familiar with taking diet histories can either gather Photocopy the diet history form the pertinent information on pages 47 and 48 for your clients, directly from a client during or download a customizable PDF the visit or review the diet of the same form from history form for completeness and accuracy once the CompendiumVet.com. client has filled it out.

CompendiumVet.com | January 2009 | Compendium: Continuing Education for Veterinarians®

Negotiating a Diet Change

QuickNotes Making an effort to talk with pet owners about their beliefs, concerns, and expectations can result in better adherence to recommendations.

The information obtained in the diet history will be invaluable for making appropriate and, hopefully, acceptable dietary recommendations for your patients. Knowing a pet’s current diet and any recent changes to it will inform your decision about what kind of dietary modification may be necessary to address the pet’s health condition and what kind of diet the pet may find most acceptable. Being aware of owner preferences and potential obstacles to change will help you tailor your recommendations not only to the pet but also to the entire household to ensure the greatest probability of success and adherence. Understanding the client’s attitude toward, and concerns about, the dietary management of pet dogs and cats will present you with the opportunity to open a dialogue with the client about pet nutrition and educate him or her about the reasons for your recommendations. Investigations in human medicine have found that when physicians make an effort to talk with patients about their knowledge, beliefs, concerns, and expectations about their condition, the result is better adherence to treatment regimens.2 Exploration of all of these issues from a patient’s perspective on his or her illness permits the attending health professional to address deficiencies in knowledge or understanding of the condition and its treatment and the patient’s ability and willingness to pursue a particular course of therapy. In veterinary medicine, the owner speaks for the patient, but the same principle applies. With regard to dietary practices, despite a basic uniformity in nutritional requirements and physiologic needs, there is considerable variation in what humans eat. In the case of pet dogs and cats, their owners largely determine what they eat on a daily basis. Yet in many, if not most, cases, client education alone will not succeed in changing habits and behaviors relating to how a pet is fed. Just as a person’s social and cultural context will influence his or her own dietary habits, it will also have an impact on how and what that person feeds a pet. Therefore, it is important to consider the social and cultural aspects of owners’ food consumption in order to communicate effectively with them about their pets’ nutritional needs and appropriate dietary management, particularly if you are attempting to change current feeding practices.3

HEALTHY BITES

To get an accurate account of the foods fed to a pet on a typical day: Find out if you are speaking to the person responsible for feeding the pet. Have a diet history form available that the client can take home so he or she can check the labels and measure the amounts of food that the pet is fed (see pages 47 and 48 or CompendiumVet.com for a sample diet history form). Request that dry pet foods be measured with an 8-oz kitchen measuring cup. Ask speciﬁcally about the different treats and supplemental foods a pet might receive (e.g., commercial treats, table foods and scraps, oral hygiene products, foods used as rewards, foods used for administering pills, dietary supplements).

Conclusion The information that can be obtained from a diet history can greatly facilitate the process of implementing dietary therapy for a patient. It can help not only in making an appropriate diet selection and accurate feeding recommendations but also in understanding the pet owner’s rationale for current feeding practices and assessing any concerns that may arise from a diet change. By anticipating problems, you should be able to craft the dietary intervention in a way that will be acceptable to the pet’s household or, at the very least, to communicate more effectively with the pet owner about the rationale for the changes in feeding management. You will be in a better position to explain why you feel the changes you are proposing are in the pet’s best interest and to look for compromise when your recommendations and the pet owner’s preferences are in conﬂict. References 1. Freeman LM, Rush JE, Markwell PJ. Dietary patterns of dogs with cardiac disease. J Nutr 2002;132:1632S-1633S. 2. The “why”: a rationale for communication skills teaching and learning. In: Kurtz S, Silverman J, Draper J. Teaching and Learning Communication Skills in Medicine. 2nd ed. San Francisco: Radcliffe Publishing; 2005:13-27. 3. Michel KE. Unconventional diets for dogs and cats. Vet Clin North Am Small Anim Pract 2006;36:1269-1281.

Compendium: Continuing Education for Veterinarians® | January 2009 | CompendiumVet.com

Letters The Curious Case of the Cat with the Munchies We found the article “Five Common Toxins Ingested by Dogs and Cats” extremely interesting and practical. We recently treated a 5-month-old domestic shorthaired cat for marijuana toxicity following ingestion of a “hash brownie.” The cat presented with perplexing sudden-onset neurologic signs and hypothermia (temperature 94.5°F [34.7°C]). With gentle coaxing, the owners admitted the source of the problem. (The brownie had been carefully wrapped in plastic ﬁlm and hidden but had disappeared while the patient was alone in the house. Clawed plastic and crumbs were found at the scene.) At the time, we found little information in the literature speciﬁcally on cases of feline marijuana ingestion. To our knowledge (and anecdotally), marijuana toxicity in cats is more likely to occur via inhalation when owners blow smoke in the cat’s face, rather than via dietary indiscretion, as is more common in dogs. In this case, we did not ascertain the ingested dose and did not know how long the patient would take to recover. Hypothermia persisted for approximately 24 hours. One of the signs not mentioned in the article by Drs. Luiz and Heseltine was marked polyphagia. During hospitalization, our patient ate ravenously. At one point, the patient defecated, passing a piece of a shoelace. This may have been ingested as a result of the cat’s marijuana-enhanced appetite before hospitalization, suggesting that gastrointestinal foreign bodies are a potential side effect of marijuana toxicity (as is chocolate toxicity, if marijuana is ingested in a brownie). The patient was discharged 3 days later when the neurologic signs resolved, although the owner reported that the cat had a “lazy eye” for 2 weeks after discharge.

Drs. Luiz and Heseltine mentioned drug testing as a means of confirming the diagnosis. We did not do this at the outset due to the client’s financial constraints. When we undertook a detailed literature search and realized so little was known about feline toxicity due to Cannabis sativa, we offered to cover the cost of toxicology testing. The owners allowed us to collect a urine sample from the patient via cystocentesis; however, the sample, collected 14 days after ingestion, returned a negative result. THC may be detectable in human urine samples for 4 to 6 weeks, but the time frame in which it remains detectable in samples from companion animal species is not known, according to the pathologist at the laboratory to which we submitted the sample (Dr. Bruce Duff at Symbion Vetnostics). The recommended time frame for submission of samples is within 48 hours of exposure to the toxin. In this case, we are confident the patient was suffering from marijuana toxicity. The negative urinalysis result may be due to the fact that a young, lean cat can metabolize marijuana relatively rapidly. Fortunately, these cases

CE Article #1

Five Common Toxins Ingested by Dogs and Cats Julie Ann Luiz, DVM University of Hawaii at Hilo

Johanna Heseltine, DVM, MS, DACVIM Oklahoma State University

ABSTRACT: Substances that are toxic to pets are present in most households. Early identification of intoxication is crucial to preventing or minimizing gastrointestinal absorption of toxins.The history, clinical signs, and laboratory test results can be used to make a presumptive diagnosis and begin therapy. nce absorbed from the gastrointestinal (GI) tract, many toxins lack a specific antidote and are associated with severe systemic effects that are difficult to treat. Therefore, prompt decontamination is the first step in managing patients that have ingested toxic materials. If the toxin ingested is known, therapy should be initiated before clinical signs develop. This article discusses the general principles for minimizing GI absorption of ingested toxins and the clinical presentation and management of toxicosis caused by five commonly ingested household substances: anticoagulant rodenticides, ethylene glycol (EG), marijuana, chocolate, and metaldehyde.

DECONTAMINATION STRATEGIES FOR ORALLY INGESTED TOXINS GI decontamination techniques are used to prevent or limit the absorption of ingested toxins. Because many toxins lack a specific antidote, decreasing the amount of toxin absorbed may be life saving, and decontamination strategies should begin as soon • Take CE tests as possible after ingestion of a • See full-text articles toxic substance. Most decontCompendiumVet.com amination methods practiced COMPENDIUM

in veterinary medicine are derived from the human medical literature. Decontamination and treatment strategies for the toxins discussed in this article are summarized in Table 1.

Emesis Induction If the owner suspects toxicosis and calls the clinic before presenting the animal, the veterinarian must consider the risks and benefits of instructing the owner to administer an emetic.1 Productive emesis requires the presence of food or liquid in the stomach, especially for retrieval of small volumes of toxin.2 Removal of the poison from the stomach is most effective within 1 hour of ingestion, is useful up to 2 hours after ingestion, and is of limited benefit more than 4 hours after ingestion.2,3 Early emesis may remove up to 80% of the ingested material.3 Induction of emesis is contraindicated for corrosive and caustic materials, as well as for petroleum distillates and other volatile materials that may result in aspiration pneumonia. 2,3 Vomiting should not be induced in patients that are depressed or have decreased consciousness or those that have seizures or are likely to seizure.2,3 Emetics should not be administered if the patient has already vomited.2

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are rare and—when they do occur— carry a good prognosis. Nonetheless, we encourage colleagues treating known or strongly suspected cases of marijuana toxicity to submit samples for toxicology screening and to share their data. Drs. Anne Fawcett and Angela Phillips Sydney Animal Hospitals Inner West Stanmore, NSW Australia

DO YOU HAVE SOMETHING TO SAY? Send your letters, suggestions, comments, or questions to E-MAIL editor@ CompendiumVet.com FAX 800-556-3288 WRITE Compendium, Veterinary Learning Systems 780 Township Line Road, Yardley, PA 19067

More letters are online at CompendiumVet.com

CompendiumVet.com | January 2009 | Compendium: Continuing Education for Veterinarians®

Antioxidants in Cancer Treatment: Helpful or Harmful? ❯❯ Lisa M. Freeman, DVM, PhD, DACVN,a Tufts University

Abstract: Nutrition is an important component of the care of dogs and cats with cancer, and dietary supplement use is common in this patient population. Antioxidants are thought to be among the most commonly used supplements. While antioxidants have potential benefi ts for cancer patients, they also may have detrimental effects. Therefore, information regarding the overall diet, including dietary supplements, should be collected for every cancer patient and carefully assessed, with specific attention to antioxidants, to identify areas in which the patient’s medical care can be optimized. eterinarians are commonly faced with to avoid excesses of overall calories and indiquestions from pet owners about nutri- vidual nutrients. Obesity resulting from excestion, but when an animal has cancer, sive caloric intake is a common problem in such questions are even more likely. Most own- animals with cancer.1,2 Body weight, body ers of dogs and cats with cancer want to know condition score, and muscle condition (i.e., everything from whether diet contributed to whether muscle loss is occurring) should be the development of the cancer to whether assessed at each visit. Obtaining a thorough they should change their pet’s diet to whether diet history allows the veterinarian to deterdietary supplements should be administered mine whether the animal is eating an approas part of their pet’s treatment. Advertisements priate diet, whether deficiencies or excesses for dietary supplements abound in magazines are likely to occur, and whether components for pet owners and veterinarians alike, and it of the diet are working with or against the can be tempting for owners of pets with can- selected therapeutic plan for the patient. This cer to believe the claims of disease treatments information can then be used to make necesor cures that are supposed to come from a sary modifications to ensure optimal care. few pills. If owners do not ask their veterinarians questions about these claims, they often The Importance of Diet History use the Internet to try to get the answers for Dietary supplementation is extremely comthemselves. Therefore, it is important to be mon in today’s society. More than half of all aware of both the potential benefits and risks Americans take dietary supplements on a regular basis.4–6 Fewer pets in the general populaof dietary supplements. tion receive dietary supplements; in one study Nutrition in Pets With Cancer of pet owners, approximately only 10% of dogs Nutrition should be an integral part of the and cats were receiving supplements, with management of every cancer patient. Cancer multivitamins, chondroprotectives, and fatty patients may be predisposed to weight loss, acid supplements being the most common.7 malnutrition, and specific nutrient deficien- However, in populations with disease condicies during treatment. Therefore, it is impor- tions, dietary supplement use is higher. Dietary tant to maintain optimal weight and prevent supplements are used in 31% of dogs and 13% nutritional deficiencies in these patients to of cats with cardiac disease, respectively,8,9 and improve their outcome.1–3 It is also important in >50% of dogs and cats with cancer.10 People

QuickNotes It is important to maintain optimal weight and prevent nutritional deﬁciencies in cancer patients to improve their outcome.

Dr. Freeman discloses that she has received research funding from Nestlé Purina PetCare, Boehringer Ingelheim, and the Waltham Centre for Pet Nutrition and that she has served on a Nestlé Purina Scientiﬁc Advisory Council.

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What do dogs who take e VETORYL (trilostane) have in common? ®

Results like these.

Prior to VETO RYL treatment

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treatment Following 3 months of with VETORYL

VETORYL Capsules contain the active ingredient trilostane, which blocks the excessive production of cortisol. Daily administration of VETORYL can greatly reduce the clinical signs associated with Cushing’s syndrome, enhancing the quality of life for both dog and owner. For more information, visit www.VETORYL.com. Contact your local veterinary distributor to order VETORYL Capsules today!

Following 9 months of treatment with VETO RYL

(trilostane)

Photographs courtesy of Carlos Melian, DVM, PhD

VETORYL is a trademark of Dechra Ltd. ©2009, Dechra Ltd. NADA 141-291, Approved by FDA As with all drugs, side effects may occur. In field studies, the most common side effects reported were poor/reduced appetite, vomiting, lethargy, diarrhea, and weakness. Occasionally, more serious side effects, including severe depression, hemorrhagic diarrhea, collapse, hypoadrenocortical crisis, or adrenal necrosis/rupture may occur, and may result in death. VETORYL Capsules are not for use in dogs with primary hepatic or renal disease, or in pregnant dogs. Refer to the prescribing information for complete details or visit www.VETORYL.com. VTYL0209-01-47122-CPD

See Page 156 for Product Information Summary

VETORYL Capsules (trilostane) ®

30 mg and 60 mg strengths Adrenocortical suppressant for oral use in dogs only

with chronic diseases use supplements even more commonly than the general population, and only a small proportion of these patients tell their health care providers about their supplement use.11 With the increase in supplement use in populations with diseases comes an increased risk for interaction between supplements or between supplements and medications. Because animals with cancer are one of the most likely populations to be receiving dietary supplements, an important part of a thorough diet history is to specifically ask owners if they are giving supplements to their pets. A thorough diet history is one of the keys to providing optimal care for animals with cancer. Questions should include the specific food (brand and specific type), amounts and frequency of feeding, types and amounts of treats and table foods, whether the animal is eating an unconventional diet (e.g., homemade, raw meat), and whether dietary supplements are being used. Dietary supplements can be a particular issue because owners often do not consider them to be either drugs or part of the diet. Therefore, if owners are not specifically questioned about the use of dietary supplements, they usually do not mention them. Veterinarians should ask about the types, brands, and doses of supplements being administered. This information can help to determine whether supplements are being used and dosed appropriately and whether they might interact with any drugs or nutrients being used as therapy.

BRIEF SUMMARY (For Full Prescribing Information, see package insert.) CAUTION: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. DESCRIPTION: VETORYL is an orally active synthetic steroid analogue that blocks production of hormones produced in the adrenal cortex of dogs. INDICATIONS: VETORYL Capsules are indicated or the treatment of pituitary-dependent hyperadrenocorticism in dogs. VETORYL Capsules are indicated for the treatment of hyperadrenocorticism due to adrenocortical tumor in dogs. CONTRAINDICATIONS: The use of VETORYL Capsules is contraindicated in dogs that have demonstrated hypersensitivity to trilostane. Do not use VETORYL Capsules in animals with primary hepatic disease or renal insufficiency. Do not use in pregnant dogs. Studies conducted with trilostane in laboratory animals have shown teratogenic effects and early pregnancy loss. WARNINGS: In case of overdosage, symptomatic treatment of hypoadrenocorticism with corticosteroids, mineralocorticoids and intravenous fluids may be required. Angiotensin-converting enzyme (ACE) inhibitors should be used with caution with VETORYL Capsules, as both drugs have aldosterone-lowering effects which may be additive, impairing the patient’s ability to maintain normal electrolytes, blood volume and renal perfusion. Potassium-sparing diuretics (e.g., spironolactone) should not be used with VETORYL Capsules as both drugs have the potential to inhibit aldosterone, increasing the likelihood of hyperkalemia. HUMAN WARNINGS: Keep out of reach of children. Not for human use. Wash hands after use. Do not empty capsule contents and do not attempt to divide the capsules. Do not handle the capsules if pregnant or if trying to conceive. Trilostane is associated with teratogenic effects and early pregnancy loss in laboratory animals. In the event of accidental ingestion/overdose, seek medical advice immediately and take the labeled container with you. PRECAUTIONS: Hypoadrenocorticism can develop at any dose of VETORYL Capsules. A small percentage of dogs may develop corticosteroid withdrawal syndrome within 10 days of starting treatment. Mitotane (o,p’-DDD) treatment will reduce adrenal function. Experience in foreign markets suggests that when mitotane therapy is stopped, an interval of at least one month should elapse before the introduction of VETORYL Capsules. The use of VETORYL Capsules will not affect the adrenal tumor itself. Adrenalectomy should be considered as an option for cases that are good surgical candidates.

QuickNotes

There is a great deal of controversy among human oncologists as Antioxidants to whether antioxiAntioxidants are thought to be among the most comdants are beneﬁcial, monly used dietary supplements in animals with cancer. They are typically administered with the goal of innocuous, or aiding in the treatment of cancer, enhancing immune detrimental.

function, or reducing treatment toxicity. Endogenous antioxidants include enzymes (e.g., glutathione peroxidase, superoxide dismutase), free radical scavengers (e.g., vitamins A, C, and E), and metal chelators (e.g., transferrin). Normally, these antioxidants compensate for the production of oxidants known as reactive oxygen species (e.g., hydrogen peroxide, superoxide anions, hydroxyl radicals), which are normal by-products of

ADVERSE REACTIONS: The most common adverse reactions reported are poor/reduced appetite, vomiting, lethargy/dullness, diarrhea, and weakness. Occasionally, more serious reactions including severe depression, hemorrhagic diarrhea, collapse, hypoadrenocortical crisis, or adrenal necrosis/rupture may occur, and may result in death. ORY FORM DIET HIST Stamp clinic

information below:

_______ ________________ ________________ ________ Date: ________ ________________ ________________ Case Number: n _______ Owner Informatio ________________ ________________ ________ Name: ________ ________________ ________ ________________ Email address: ________________ ________________ __________ Phone (home): ________________ __________ ________________ Phone (cell): ________________ call:_____________ Best time to

DIET HISTORY FORM Behavior

❏ Yes

❏ No

How does your pet act toward towa food? ❏ Greedy ❏ Indifferen Indifferent ❏ Shows avoidance Has your pet’s attitude toward towa food changed? If so, describe: _______________________ ________________________ ________________________ ____ _______________________ ________________________ ________________________ ____ _______________________ ________________________ ________________________ ____ _______________________ ________________________ ________________________ ____ If you have other pets, is this pet dominant or submissive to them? ❏ Dominant ❏ Submis Submissive Has your pet recently lost or ggained weight? If so, please describe: _______________________ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ Have there been any recent ch changes in activity level? __________ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ Have you observed any of the ffollowing: Nausea/salivation ❏ Yes ❏ No Diffificulty chewing ❏ Yes ❏ No Diffificulty swallowing ❏ Yes ❏ No Vomiting ❏ Yes ❏ No Diarrhea ❏ Yes ❏ No Constipation ❏ Yes ❏ No Have there been any changes in urination? ❏ Yes ❏ No

the day? for your pet during ed food sources Is food left out other, unmonitor have access to cats)? Does your pet food left for outdoor by neighbor, (e.g., treats fed _______ ❏ Yes ❏ No ________________ ____ describe:_________ If yes, please ________________ ________________ ____ ________________ ________________ ________________ ____ ________________ ________________ ________________ ____ ________ ________ ________________ ________________ to each other’s ________________ _ have access one pet, do they ________________ than Reason for Visit more ________ If you have ____ please describe: ________________ ❏ No If yes, ________________ ___________ ____________ food? ❏ Yes ________________ ________________ ____________ ________ ____ ________ ________________ ________________ ________________ ________________ ________________ ________________ ____________ ________________ ________________ ________ ____ ___ hics ________ ________________ ________________ Household Demograp ? ________ ________________ ____ are in your household are they? ________________ ________________ How many adults , and how old ________________ ____ ____ are in your household ________________ ________________ ________________ How many children ________________ ____ ________________ ____________ ________________ ________________ ________________ ________________ ________ ________ ____ ________ ________________ ________________ ________________ ________________ food? ________ ____ ________________ store your pet’s ____________ How do you ________________ ________________ ________________ ________ ________ ____ ________ ❏ Both ❏ Outdoors ________________ ________________ ________________ ❏ Indoors ________________ pet housed? ____________ please list species ________________ Where is your ❏ No If so, ________________ Yes ❏ ________ other pets? ________________ Do you have or outdoors. ____ they live indoors Diet and specify if ________________ ____ ________________ Activity For each of the following categories, catego ________________ ________________ list the brand names (if appliyour pet? ____ ________________ cable) and amounts of all foods your How active is ❏ Average pet eats daily, as well as how ________________ ________________ Very active ❏ ________ e often each food is fed (e.g., twice ____ ________ twic a day). ❏ Hyperactiv ________________ ________________ ❏ Hardly moves Commercial foods ____ ________________ ❏ Not very active ________________ ________________ your pet walked? ________________________________________________ ________________ ❏ Once a day __ How often is ____ ________________ ❏ 1-2 times/day times/day ________________________________________________ ❏ At least 3 __ ____ ____ ent Never No ❏ ________ ❏ ________________________________________________ ❏ Yes Feeding Managem ❏ Seldom __ ________________ ____ ____ feeds your pet? access to a yard? ________________ ❏ Yes ❏ No ________________________________________________ Who typically Do you have __ pet? ____ ____ ________________ your No ________ ________ exercise ________ ________________________________________________ ________ ❏ Yes ❏ Is it difﬁcult to ___ ________________ ____ __________ be increased? ________________ ❏ Yes ❏ No Commercial treats; dental hygiene products ________________ Can exercise ____ training? pet fed? ________ participated in ________________ When is your ❏ Yes ❏ No ________________________________________________ Has your pet ___ ____ ________________ competition? ____ participated in ________________ ________________ ________________________ Has your pet Systems ___ ________________________ ____ ________________ Learning ____ ________ ________ ©2009 Veterinary ________ ________ ________________________________________________ ___ ________________ ____ ________________ ________________________________________________ ___ ____ ________________________________________________ ___ ____

(trilostane)

n Age: ________ Pet Informatio __________ ________________ ___________ Name: ________ Breed: ________ _____________ ❏ Yes ❏ No Species: ________ Neutered/spayed: ❏ Female _____________ Gender: ❏ Male Usual weight: _____________ Current weight: _____ score (1–9): ❏ Severe Body condition None ❏ Mild wasting ❏ muscle of Evidence

Distributed by: Dechra Veterinary Products 7015 College Boulevard, Suite 525 Overland Park, KS 66211 www.VETORYL.com 866-933-2472 VETORYL is a trademark of Dechra Ltd. © 2009, Dechra Ltd. NADA 141-291, Approved by FDA

Table foods or scraps; home-prepared

foods

________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ Dietary supplements; food used to give pills ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ List anything else given by mouth (e.g., medications): ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ Is your pet’s current diet a change from its typical diet? ❏ Yes

❏ No

If so, please describe the change and why the diet was changed. ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ Are you open to making a change in your pet’s diet? ❏ Yes ❏ No What are your pet’s food preferences?______________ ________ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ What foods does your pet refuse? ________________________ _ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ Are there foods to which your pet is allergic? ❏ Yes ❏ No If so, which foods? ________________________ ____________ ________________________________________________ ____ ________________________________________________ ____ ________________________________________________ ____ ©2009 Veterinary Learning Systems

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WEB EXCLUSIVE Download a customizable PDF of the diet history form from

CompendiumVet.com.

Compendium: Continuing Education for Veterinarians® | April 2009 | CompendiumVet.com

CONTRIBUTED BY THE AMERICAN COLLEGE OF VETERINARY NUTRITION

aerobic metabolism. However, when oxidant production is excessive or antioxidant production is insufficient, an imbalance known as oxidative stress occurs. Excessive oxidants damage DNA, lipids, and proteins and increase the production of inflammatory mediators, among other deleterious effects. It has been hypothesized that oxidative stress increases the risk for certain types of cancer, and it is theorized to play an important role in the aging process. Therefore, antioxidants (both endogenous and supplemental) have been extensively studied in terms of their efficacy in reducing the development of cancer, with variable success. Another area of great interest and controversy is the use of antioxidants during the treatment of cancer, whether alone or in conjunction with chemotherapy or radiation therapy. Antioxidants have a number of potential benefits in cancer patients. Oxidative stress has been associated with increased morbidity and mortality for a number of human cancers, and recent studies have demonstrated oxidative stress in dogs with mammary tumors and lymphoma.12–14 Reactive oxygen species can contribute to malignant transformation and neoplastic cell proliferation and so could contribute to disease progression. Therefore, boosting antioxidant reserves and reducing oxidative stress might reduce tumor growth or metastasis. Another potential benefit of antioxidants is protection against radiation- and chemotherapyinduced adverse effects (e.g., gastrointestinal, renal, and cardiac toxicities); some, but not all, studies in rodent models and people have shown modest benefits. These potential benefits are the rationale behind the high use of various antioxidants during cancer treatment. However, there also are potential detrimental effects of antioxidants in patients undergoing treatment for cancer. The efficacy of radiation therapy and of many chemotherapeutic agents depends on the development of reactive oxygen species. Therefore, reduced treatment efficacy is possible if antioxidants are used concurrently with these therapies. Because of these competing effects, there is a great deal of controversy among human oncologists as to whether antioxidants are beneficial, innocuous, or detrimental.15–17 Antioxidants do not all behave similarly, and some have significantly different effects depending on their dose and form and what other medications and supple-

About ACVN

BOX 1 HEALTHY BITES

Recommended Web Sites www.acvn.org The American College of Veterinary Nutrition Offers a “Nutrition Resources” page that includes contact information for ACVN diplomates who do nutrition consultations or formulate homemade diets. www.consumerlab.com Consumerlab.com This group performs independent testing of dietary supplements for purity, potency, and bioavailability. vm.cfsan.fda.gov/~dms/supplmnt.html The US Food and Drug Administration Center for Food Safety and Applied Nutrition Resource for regulatory and safety issues, adverse event reporting, meetings, and industry information. www.mayoclinic.com/health/ druginformation/DrugHerbIndex The Mayo Clinic Lists information and grades recommendations for the use of some drugs and supplements. nccam.nih.gov National Institutes of Health National Center for Complementary and Alternative Medicine Provides information on research into complementary and alternative healing practices. dietary-supplements.info.nih.gov National Institutes of Health Ofﬁce of Dietary Supplements Includes fact sheets, safety notices, and the International Bibliographic Information on Dietary Supplements database. www.quackwatch.org Quackwatch This site calls itself a “guide to health fraud, quackery, and intelligent decisions.” www.nal.usda.gov/fnic/etext/000015.html The US Food and Drug Administration Food and Nutrition Information Center Includes general supplement and nutrition information and links to a variety of dietary supplement Web sites.

Founded in 1988, the primary objective of the American College of Veterinary Nutrition (ACVN) is to advance the specialty area of veterinary nutrition and increase the competence of those who practice in this ﬁeld by establishing requirements for certiﬁcation in veterinary nutrition, encouraging continuing professional education, promoting research, and enhancing the dissemination of new knowledge of veterinary nutrition through didactic teaching and postgraduate programs. For more information, contact: American College of Veterinary Nutrition, c/o Dawn Cauthen, Administrative Assistant, School of Veterinary Medicine: Dept. of Molecular Biosciences One Shields Avenue Davis, California 95616-8741 Telephone: 530-752-1059 Fax: 530-752-4698 Email: dawncauthen@yahoo.com Web: acvn.org

QuickNotes Once veterinarians determine what foods and supplements owners are giving their pets, they may need to gather additional information about their safety, efﬁcacy, and potential for interaction.

www.usp.org/USPVerified US Pharmacopeia Dietary Supplement Verification Program (voluntary) This group performs independent testing of “dietary supplement finished products” for purity, potency, and quality and awards its Verified Dietary Supplement Mark to products that meet its criteria.

CompendiumVet.com | April 2009 | Compendium: Continuing Education for Veterinarians®

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ments are being concurrently administered. Therefore, evaluating whether one has benefits (or adverse effects) can be a complicated endeavor. In addition to the specific pros and cons of antioxidants are the general issues that are of concern with all human and veterinary dietary supplements: safety, efficacy, dose, bioavailability, dissolvability, and quality control. Until additional data are available, I recommend against the use of antioxidants during radiation therapy or chemotherapy in dogs and cats with cancer.

Conclusion Once veterinarians determine what foods and supplements owners are giving their pets, they may need to gather additional information about their safety, efﬁcacy, and potential for interaction with each other and other therapies. Some of the Web sites listed in BOX 1 can be useful for this purpose. Because there is little governmental regulation of dietary supplements, pet owners should consider selecting dietary supplements that bear the logo of the Dietary Supplement Veriﬁcation Program, which tests human dietary supplements for ingredients, concentrations, dissolvability, and contaminants. Another good resource is Consumerlab.com, which performs independent testing of health and nutrition products (primarily human supplements, but also some pet products). As of 2008 (2009 or 2010 for smaller companies), the US Food and Drug Administration is instituting regulations that require supplements to be made using Good Manufacturing Practices and to meet quality standards.18

References 1. Michel KE, Sorenmo K, Shofer FS. Evaluation of body condition and weight loss in dogs presented to a veterinary oncology service. J Vet Intern Med 2004;18:692-695. 2. Weeth LP, Fascetti AJ, Kass PH, et al. Prevalence of obese dogs in a population of dogs with cancer. Am J Vet Res 2007;68:389-398. 3. Baez JL, Michel KE, Sorenmo K, Shofer FS. A prospective investigation of the prevalence and prognostic significance of weight loss and changes in body condition in feline cancer patients. J Feline Med Surg 2007;9:411-417. 4. Balluz LS, Kieszak MA, Philen RM, et al. Vitamin and mineral supplement use in the United States: results from the third national health and nutrition examination survey. Arch Fam Med 2000;9:258-262. 5. Balluz LS, Okoro CA, Bowman BA, et al. Vitamin or supplement use among adults, behavioral risk factor surveillance system, 13 states, 2001. Public Health Rep 2005;120:117-123. 6. Archer SL, Stamler J, Moag-Stahlberg A, et al. Association of dietary supplement use with speciﬁc micronutrient intakes among middle-aged American men and women: the INTERMAP study. J Am Diet Assoc 2005;105:1106-1114. 7. Freeman LM, Abood SK, Fascetti AJ, et al. Disease prevalence among dogs and cats in the United States and Australia and proportions of dogs and cats that receive therapeutic diet or dietary supplements. JAVMA 2006;229:531-534. 8. Freeman LM, Rush JE, Cahalane AK, et al. Dietary patterns in dogs with cardiac disease. JAVMA 2003; 223:1301-1305.

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9. Torin DS, Freeman LM, Rush JE. Dietary patterns of cats with cardiac disease. JAVMA 2007;230:862-867. 10. Lana SE, Kogan LR, Crump KA, et al. The use of complementary and alternative therapies in dogs and cats with cancer. JAAHA 2006;42:361-365. 11. Ball SD, Kertesz D, Moyer-Mileur LJ. Dietary supplement use is prevalent among children with a chronic disease. J Am Diet Assoc 2005;105:78-84. 12. Szczubial M, Kankofer M, Lopuszynski W, et al. Oxidative stress parameters in bitches with mammary gland tumours. J Vet Med A Physiol Pathol Clin Med 2004;51:336-340. 13. Vajdovich PT, Kriska T, Mezes M, et al. Redox status of dogs with non-Hodgkin lymphomas. An ESR study. Cancer Lett 2005;224:339-346. 14. Winter JL, Barber L, Griessmayr PC, et al. Antioxidant status and biomarkers of oxidative stress in canine lymphoma. J Vet Intern Med 2009;23:311-316. 15. D’Andrea GM. Use of antioxidants during chemotherapy and radiotherapy should be avoided. CA Cancer J Clin 2005;55:319-321. 16. Block KI, Koch AC, Mead MN, et al. Impact of antioxidant supplementation on chemotherapeutic efﬁcacy: A systematic review of the evidence from randomized controlled trials. Cancer Treat Rev 2007;33:407-418. 17. Moss RW. Do antioxidants interfere with radiation therapy for cancer? Integr Cancer Ther 2007;6:281-292. 18. United States Food and Drug Administration. Fact sheet: dietary supplement current good manufacturing practices (CGMPs) and interim ﬁnal rule (IFR) facts. Accessed March 2009 at www.cfsan.fda.gov/~dms/dscgmps6.html.

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My patients rely on me every day. And I rely on Baytril®. Because when it comes to infections, it’s on my side – an eﬀective partner I can count on. Federal (U.S.A.) law restricts this drug to use by or on the order of a licensed veterinarian. In animal safety studies, isolated incidences of vomition and inappetence were reported. © 2009 Bayer HealthCare LLC, Animal Health Division, Shawnee Mission, Kansas 66201. Bayer, the Bayer Cross, Baytril and Right the ﬁrst time are registered trademarks of Bayer.

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US Pet Food Regulation:

Hot Topics

❯❯ David A. Dzanis, DVM, PhD, DACVNa Dzanis Consulting & Collaborations Santa Clarita, California

Abstract: The US Food and Drug Administration (FDA) Amendments Act of 2007 mandates promulgation of new federal regulations regarding processing, ingredient, and labeling standards for pet foods. Veterinary organizations have submitted comments to assist FDA in this matter. The Association of American Feed Control Ofﬁcials (AAFCO) is also considering changes that will affect state regulation of pet foods, including revision of the AAFCO Dog and Cat Food Nutrient Proﬁles and feeding trial protocols, an American College of Veterinary Nutrition proposal to mandate calorie content statements on all dog and cat food labels, and new Good Manufacturing Practices regulations for all animal feeds.

At a Glance US Food and Drug Administration Page 462

Association of American Feed Control Ofﬁcials Page 463

Dr. Dzanis is a consultant for the pet food and related industries on matters pertaining to nutrition, labeling, and regulation. He formerly served as the veterinary nutritionist for the US Food and Drug Administration and represented the agency on the Association of American Feed Control Ofﬁcials Pet Food Committee.

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everal changes to the means by which do not specify rules for declaration of nutrient pet foods are regulated are forthcom- content, substantiation of nutritional adequacy, ing. Some of these changes are in reac- or other important aspects of pet food labeltion to the widely reported recall of dog and ing.1 These issues are instead addressed in the cat foods in 2007, while others were under regulations of states that have adopted the way well before the recall. In both cases, vet- Association of American Feed Control Officials erinary organizations are involved in the pro- (AAFCO) Model Bill and Regulations.2 cess. Because pet owners often consult with veterinarians on matters relating to pet food, FDA Amendments Act of 2007 it behooves practitioners to be familiar with Subsequent to a hearing regarding the 2007 recall, the US Congress passed the FDA these developments. Amendments Act of 2007 (FDAAA).3 Most of US Food and Drug Administration the FDAAA does not pertain to pet foods, but The Center for Veterinary Medicine within the what it does include with respect to pet foods US Food and Drug Administration (FDA) has is far-reaching. The responsibility is placed authority over all animal feeds in interstate on FDA to improve its abilities to detect and commerce. While this authority includes pet respond to future incidents involving pet foods (complete and balanced foods, treats, food–borne illness, including better communisupplements, and edible chews), there are no cation with both the public and industry on federal regulations stipulating requirements for the status of recalls. Establishment of a reportpet foods specifically (with minor exceptions, able food registry, wherein pet food compasuch as specifying the conditions of use for nies must promptly report incidents that may iron oxide as a coloring agent in dog and cat lead to unsafe products, is also a component of foods). For example, while FDA regulations set the FDAAA. This mandatory reporting system forth the basic labeling requirements for all ani- went into effect in September 2009.4 While the words themselves are few (BOX 1), mal feeds (e.g., statement of identity, net weight declaration, ingredient declaration, manufac- the FDAAA requirement for FDA to establish turer’s or distributor’s name and address), they specific pet food regulations, especially with

Compendium: Continuing Education for Veterinarians® | October 2009 | CompendiumVet.com

CONTRIBUTED BY THE AMERICAN COLLEGE OF VETERINARY NUTRITION About ACVN regard to nutrition and labeling, may have the biggest impact on commercial pet foods. FDA has invited public comments on this matter, and the American College of Veterinary Nutrition (ACVN), American Academy of Veterinary Nutrition (AAVN), and AVMA have all submitted recommendations. Among the many issues raised by these organizations are the need for calorie content statements, replacement of the crude ﬁber label guarantee with a more nutritionally relevant measure, and wording on therapeutic diet labels to advise veterinarians and the public that efﬁcacy claims for such products may not have been subject to regulatory scrutiny. The complete comments of these groups, as well as those of other organizations and individuals, may be viewed by visiting regulations.gov (search on “FDA-2007-N-0442” in the “Keyword” box). While the FDAAA mandates that these regulations be promulgated by September 2009, the proposed rules had not been made available for public review and comment at the time this article went to press.

Other Actions For years before the 2007 recall, FDA had been developing its Animal Feed Safety System (AFSS), a “comprehensive” and “risk-based” program designed to “identify and address gaps” in the management of risk to human and animal health from exposure to animal feeds (including pet foods).5 Components of the system include the ingredient approval process, contaminant limits, process control (i.e., Good Manufacturing Practices; GMPs), and regulatory oversight. FDA has been intimately involved in the AAFCO process for many years. In August 2007, FDA and AAFCO signed a Memorandum of Understanding with respect to the latter’s Feed Ingredient Deﬁnition procedure.2 While not the same as a formal Food Additive Petition under FDA regulations, this memorandum increases FDA oversight of the AAFCO procedures for new, amended, or deleted ingredients. FDA has also commissioned a report from the National Research Council (NRC) to help in its safety assessment of novel ingredients.6

BOX 1 EXCERPT FROM THE FDAAA AFFECTING PET FOODS3

SEC. 1002. ENSURING THE SAFETY OF PET FOOD. (a) Processing and Ingredient Standards. Not later than 2 years after the date of the enactment of this Act, the Secretary of Health and Human Services (referred to in this title as the “Secretary”), in consultation with the Association of American Feed Control Ofﬁcials and other relevant stakeholder groups, including veterinary medical associations, animal health organizations, and pet food manufacturers, shall by regulation establish (1) ingredient standards and deﬁnitions with respect to pet food; (2) processing standards for pet food; and (3) updated standards for the labeling of pet food that include nutritional and ingredient information.

Association of American Feed Control Ofﬁcials Nutritional Adequacy

Founded in 1988, the primary objective of the American College of Veterinary Nutrition (ACVN) is to advance the specialty area of veterinary nutrition and increase the competence of those who practice in this ﬁeld by establishing requirements for certiﬁcation in veterinary nutrition, encouraging continuing professional education, promoting research, and enhancing the dissemination of new knowledge of veterinary nutrition through didactic teaching and postgraduate programs. For more information, contact: American College of Veterinary Nutrition, c/o Dawn Cauthen, Administrative Assistant, School of Veterinary Medicine: Dept. of Molecular Biosciences One Shields Avenue Davis, California 95616-8741 Telephone: 530-752-1059 Fax: 530-752-4698 Email: dawncauthen@yahoo.com Web: acvn.org

The AAFCO Model Regulations for Pet Food and Specialty Pet Food establish minimum nutritional requirements for dog and cat foods labeled as “complete and balanced” or identiﬁed by similar terminology.2 Before the 1990s, one method of nutritional adequacy substantiation was based on the product meeting NRC recommendations for minimum nutrient content. However, because of problems with using the NRC recommendations (which were largely based on feeding of puriﬁed laboratory diets) as they related to the practicalities

TO LEARN MORE

Dr. Dzanis’ previous article on pet food regulation, “Regulation of Pet Foods in the United States” (July 2009), is available on CompendiumVet.com.

CompendiumVet.com | October 2009 | Compendium: Continuing Education for Veterinarians®

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of commercial pet food production, an expert At the same time, the panel instituted changes panel comprising members from academia to improve the scientific rigor of the AAFCO and the industry was convened by AAFCO to feeding trial protocols (an alternative means of address these issues.7 The result of the pan- substantiating nutritional adequacy). el’s deliberation was the AAFCO Dog and Cat Neither the profiles nor the protocols have Food Nutrient Profiles, which are still in use. been revised since 1995. In 2006, NRC pubBOX 2 ACVN PROPOSAL TO AAFCO REGARDING CALORIE CONTENT STATEMENTS ON DOG AND CAT FOOD LABELSa

QuickNotes A mandatory reporting system for incidents that may lead to unsafe pet food products went into effect in September 2009.

Regulation PF9. Statements of Calorie Content (a) Except as required in PF(10), tThe label of a dog or cat food mayshall bear a statement of calorie content when the labeland meets all of the following: (1) The statement shall be separate and distinct from the “Guaranteed Analysis” and appear under the heading “Calorie Content”; (2) The statement shall be measured in terms of metabolizable energy (ME) on an “as fed” basis and must be expressed both as “kilocalories per kilogram” (“kcal/kg”) of product, and may also be expressedas kilocalories per familiar household measure (e.g., cans, cups, poundsbiscuits); and (3) The calorie content is determined by one of the following methods: A. By calculation using the following “Modified Atwater” formula: ME (kcal/kg) = 10[(3.5 × CP) + (8.5 × CF) + (3.5 × NFE)] Where: ME = Metabolizable Energy CP = % crude protein “as fed” CF = % crude fat “as fed” NFE = % nitrogen-free extract (carbohydrate) “as fed” And the percentages of CP and CF are arithmetic averages from proximate analyses of at least four production batches of the product, and the NFE is calculated as the difference between 100 and the sum of CP, CF, and the percentages of crude fiber, moisture, and ash (determined in the same manner as CP and CF); or B. In accordance with a testing procedure established by AAFCO. (4) An affidavit shall be provided upon the request of ____, substantiating that the calorie content was determined by: A. Regulation PF9(a)(3)A in which case the summary data used in the calculation shall accompany the affidavit; or B. Regulation PF9(a)(3)B in which case the summary data used in the determination of calorie content shall accompany the affidavit. (5) The calorie content statement shall appear as one of the following: A. The claim on the label or other labeling shall be followed parenthetically by the word “calculated” when the calorie content is determined in accordance with Regulation PF9(a)(3)A; or B. The claim on the label or other labeling shall be followed parenthetically by the word “fed” when the calorie content is determined in accordance with Regulation PF9(a)(3)B, and tThe value of calorie content stated on the label which is determined in accordance with Regulation PF9(a)(3)B shall not exceed or understate the value determined in accordance with PF9(a)(3)A by more than 15%. (b) Comparative claims shall not be false, misleading, or given undue emphasis and shall be based on the same methodology for the products compared. aAs originally proposed in 2005 (some revisions have been made as deliberations continue). Proposed additions and deletions

are in underline and strikethrough, respectively.

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Compendium: Continuing Education for Veterinarians® | October 2009 | CompendiumVet.com

lished a new document on the nutrient requirements of dogs and cats, including updated scientific information as well as practical considerations pertaining to pet food production.8 Currently, AAFCO has convened a new panel of experts to review the NRC publication and update the profiles as appropriate, as well as to review and revise the feeding protocols to further their scientific soundness. Some portions of the panel’s report are expected to be released for public comment in 2010.

Calorie Content Presently, except for dog and cat food products labeled lite, low calorie, less calories, or like terms, calorie content declarations on pet food labels are voluntary. As a result, many dog and cat food labels do not contain this information, and these values are often difficult to obtain from other sources. Calorie content statements are mandatory for “lite” and similarly labeled pet foods. However, some product labels avoid these specific terms and instead use wording such as weight management formula, for less active dogs, or other, similar phrases. These alternative phrases still imply control of energy intake, but because they do not expressly refer to calories, the labels do not have to declare caloric content. In 2005, ACVN submitted a proposal to AAFCO that, among other things, would mandate calorie content statements on all dog and cat food labels, including snacks and treats (BOX 2). In light of the reported high incidence of overweight and obese pets in the United States, this is a prudent action. Knowledge of calorie content in all types of foods could help veterinarians and owners prevent excess pet weight gain, not just treat the aftermath. Beyond the issue of obesity, knowledge of calorie content for a given product is helpful when determining appropriate feeding amounts for dogs and cats at any life stage, be they growing kittens, working dogs, or lactating dams; hence, limitation of the required label statement to just the “lite” and “less calories” categories of food is insufficient. The ACVN proposal has been endorsed by AAVN, AVMA, and the American Animal Hospital Association. A statistically sound survey of practicing veterinarians found that an overwhelming proportion (97%) would like to see calorie content statements on pet food

labels.9 Despite these facts, the ACVN proposal has been vigorously opposed by segments of the pet food industry. As a result, after 4 years of debate within AAFCO, deliberations on this matter are ongoing.

Good Manufacturing Practices Historically, safety of pet foods has been monitored by regulators through inspection (including sampling for analysis) of the ﬁnished product. Under this practice, a laboratory ﬁnding of product contamination with a pathogenic organism or chemical toxin could be used as evidence of adulteration so that regulatory action could be taken. However, in

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QuickNotes AAFCO has recently enacted new model regulations for GMPs that affect all animal feeds, including pet foods.

the past, regulatory officials have spent little violation of the GMPs could be de facto evidence effort on monitoring the processes that may that a product manufactured under these condilead to contamination. GMPs are in place for tions was adulterated, irrespective or in lieu of a canned products to help prevent safety issues negative laboratory finding of contamination. specifically related to the complicated sterilization process, as well as for medicated feeds Conclusion (feeds containing an approved drug, such as As evidenced by recent changes, steps to further an antibiotic or coccidiostat), but not for ani- ensure the safety of pet foods have become a high-priority matter for regulators. Other conmal feeds or pet foods in general. After a number of years of deliberation, cerns to be addressed in the near future may AAFCO has recently enacted new model reg- include establishment of FDA mandatory recall ulations for GMPs that affect all animal feeds, authority and increased oversight of imported including pet foods. These new rules establish products. By virtue of their expertise in the field additional requirements regarding handling of of animal health, veterinarians are in a unique materials, training of personnel, sanitation, pro- position to contribute their viewpoints as these cessing, transportation, and record keeping. A deliberations continue.

References 1. Code of Federal Regulations, Title 21, Part 501. Washington, DC: Government Printing Office; 2009. 2. AAFCO Official Publication. Oxford, IN: Association of American Feed Control Officials; 2008. 3. Food and Drug Administration Amendments Act of 2007. Accessed August 2009 at http://frwebgate.access.gpo.gov/cgi-bin/ getdoc.cgi?dbname=110_cong_public_laws&docid=f:publ085. 110.pdf. 4. US Food and Drug Administration. Reportable food registry. Accessed September 2009 at fda.gov/Food/FoodSafety/FoodSafety Programs/RFR/default.htm. 5. US Food and Drug Administration. Animal Feed Safety System.

Accessed February 2009 at http://www.fda.gov/cvm/AFSS.htm. 6. National Research Council. Safety of Dietary Supplements for Horses, Dogs and Cats. Washington, DC: National Academies Press; 2009. 7. Dzanis DA. AAFCO dog and cat food nutrient proﬁles. In: Bonagura JD, ed. Kirk’s Current Veterinary Therapy XIII. Philadelphia: WB Saunders; 2000:1228-1230. 8. National Research Council. Nutrient Requirements of Dogs and Cats. Washington, DC: National Academies Press; 2006. 9. Haberl A, Kilgos K, Bufﬁngton CAT. Comparison of owners’ and veterinarians’ perceptions, knowledge, and use of nutritional information on pet food labels. Proc 7th Annu Workshop Pet Food Labeling Regul 2001.

FREE CE Canine Glaucoma: Pathophysiology and Diagnosis

CONTINUED FROM PAGE 452

References 1. Abrams KL. Medical and surgical management of the glaucoma patient. Clin Tech Small Anim Pract 2001;16(1):71-76. 2. Gelatt KN, Brooks DE, Kallberg ME. The canine glaucomas. In: Gelatt KN, ed. Veterinary Ophthalmology. 4th ed. Ames, Iowa: Blackwell Publishing; 2007:753-811. 3. Knollinger AM, La Croix NC, Barrett PM, Miller PE. Evaluation of a rebound tonometer for measuring intraocular pressure in dogs and horses. JAVMA 2005;227(2):244-248. 4. Pauli AM, Bentley E, Diehl KA, Miller PE. Effects of the application of neck pressure by a collar or harness on intraocular pressure in dogs. JAAHA 2006;42(3):207-211. 5. Reilly CM, Morris R, Dubielzig RR. Canine goniodysgenesis-related glaucoma: a morphologic review of 100 cases looking at inﬂammation and pigment dispersion. Vet Ophthalmol 2005;8(4):253-258. 6. Gelatt KN, MacKay EO. Secondary glaucomas in the dog in North America. Vet Ophthalmol 2004;7(4):245-259. 7. Johnsen DA, Maggs DJ, Kass PH. Evaluation of risk factors for development of secondary glaucoma in dogs: 156 cases (19992004). JAVMA 2006;229(8):1270-1274. 8. Lannek EB, Miller PE. Development of glaucoma after phacoemulsiﬁcation for removal of cataracts in dogs: 22 cases (19871997). JAVMA 2001;218(1):70-76.

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9. Biros DJ, Gelatt KN, Brooks DE, et al. Development of glaucoma after cataract surgery in dogs: 220 cases (1987-1998). JAVMA 2000;216(11):1780-1786. 10. Gelatt KN. The canine glaucomas. In: Essentials of Veterinary Ophthalmology. Ames, Iowa: Blackwell Publishing; 2005:165-196. 11. Grozdanic SD, Matic M, Betts DM, et al. Recovery of canine retina and optic nerve function after acute elevation of intraocular pressure: implications for canine glaucoma treatment. Vet Ophthalmol 2007;10(suppl 1):101-107. 12. Martin CL. Evaluation of patients with decreased vision or blindness. Clin Tech Small Anim Pract 2001;16(1):62-70. 13. Broadwater JJ, Schorling JJ, Herring IP, Elvinger F. Effect of body position on intraocular pressure in dogs without glaucoma. Am J Vet Res 2008;69(4):527-530. 14. Miller PE, Pickett JP. Comparison of the human and canine Schiotz tonometry conversion tables in clinically normal dogs. JAVMA 1992;201(7):1021-1025. 15. Gorig C, Coenen RT, Stades FC, et al. Comparison of the use of new handheld tonometers and established applanation tonometers in dogs. Am J Vet Res 2006;67(1):134-144. 16. Miller PE, Schmidt GM, Vainisi SJ, et al. The efﬁcacy of topical prophylactic antiglaucoma therapy in primary closed angle glaucoma in dogs: a multicenter clinical trial. JAAHA 2000;36(5):431-438.

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B:8.25” T:8” S:7”

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K9 Advantix® is for use on dogs only. © 2009 Bayer HealthCare LLC, Animal Health Division, Shawnee Mission, Kansas 66201. Bayer, the Bayer Cross, K9 Advantix and Advantage are registered trademarks of Bayer.

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In collaboration with the American College of Veterinary Surgeons

Surgical Treatment of Urethral Sphincter Mechanism Incompetence in Female Dogs ❯❯ Mary A. McLoughlin, DVM, MS, DACVS ❯❯ Dennis J. Chew, DVM, DACVIMa The Ohio State University

At a Glance Urethral Sphincter Mechanism Incompetence Page 360

Diagnosis Page 361

Surgical Treatment of Urethral Sphincter Mechanism Incompetence Page 362

Medical Management of Urethral Sphincter Mechanism Incompetence in Female Dogs Page 364

Future Directions in Treatment Page 373

aDr. Chew discloses that he has

received financial support from Bayer Animal Health and Nestlé Purina PetCare Company.

360

Abstract: Urinary incontinence—loss of voluntary control over the retention and expulsion of urine—is a common medical problem in small animal patients. Incontinence occurs when pressure within the bladder exceeds urethral pressure. Incontinence may result from a variety of etiologies, including congenital anatomic abnormalities of the lower urinary and reproductive systems (ureter, bladder, bladder neck, urethra, vagina, vestibule) as well as neurologic, neoplastic, infectious, and inflammatory diseases.

Urethral Sphincter Mechanism Incompetence Urethral sphincter mechanism incompetence (USMI), also referred to as idiopathic incon tinence, spay incontinence, and hormoneresponsive incontinence, is the most common and important cause of acquired urinary incontinence in adult female dogs.1–4 USMI is largely a condition of spayed dogs, but in some breeds, such as greater Swiss mountain dogs, soft-coated wheaten terriers, Doberman pinschers, and giant schnauzers, incontinence may precede ovariohysterectomy (OVH). Congenital USMI has also been recognized as a cause of incontinence in juvenile dogs and is frequently associated with other anatomic malformations, such as ureteral ectopia and ureteroceles.1–4 Approximately 20% of female dogs have been reported to develop some degree of USMI after OVH performed between the first and second heat cycles.5 In dogs spayed before first estrus, the incidence is reported to be 9.7%.5 The incidence of incontinence may be as high as 30% in large-breed female dogs (>20 kg); in some breeds, including boxer, Doberman pinscher, rottweiler, Old

English sheepdog, and giant schnauzer, it is even higher.1,2,4,6–8 Urinary incontinence is most often reported within 3 years of spaying.1–4 There is no reported difference in the incidence of incontinence between dogs in which ovariectomy alone was performed and dogs that underwent OVH. Decreases in maximal urethral closure pressure (MUCP) and functional urethral length predictably occur during the first 12 to 18 months after neutering, resulting in a caudal shift of the urethral pressure profile and deterioration of urethral closure function. It is speculated that the decline in MUCP continues with advancing age, further contributing to the development of incontinence in later life.1,2,7,8 The term urethral sphincter mechanism incompetence was first suggested to describe weakness of the “urinary sphincter” despite the fact that no true anatomic sphincter exists at the bladder neck or proximal urethra. The smooth muscle of the proximal urethra is continuous with the detrusor muscle layer of the bladder trigone.1 Therefore, congenital anatomic abnormalities affecting the ureters, bladder neck, and proximal urethra can impair development of the normal smooth

Compendium: Continuing Education for Veterinarians® | August 2009 | CompendiumVet.com

muscle architecture in this region, contributing to incontinence.1–4 Varying amounts of fibrovascular tissue located throughout the length of the bladder neck and urethra may also play a role in maintenance of continence.1–3 Caudal displacement of the bladder into the pelvic canal is recognized as pelvic bladder syn drome.9,10 The hallmark radiographic appearance of a pelvic bladder shows abnormal elongation of the bladder, persistent caudal displacement of the bladder and bladder neck into the pelvic canal on distention, an indistinct or blunted vesicourethral junction, and a shortened urethra.9,10 Shortening of the urethra reduces exposure of the bladder neck and proximal urethral wall to the intraabdominal pressure that acts as an external occluding force.1,2,4,6–8 Abnormally short urethras are frequently noted in dogs with USMI. Pelvic bladder has been reported in male and female dogs with and without urinary incontinence.9,10 The significance of pelvic bladder and its role in the pathophysiology of USMI are not completely understood, but pelvic bladder is thought to be a contributing factor in patients with USMI.9,10 USMI is considered to be a multifactorial disorder, and the specific etiopathogenesis remains unclear.1–4,6–8 USMI in dogs has been likened to stress incontinence diagnosed in women after pregnancy, childbirth, or menopause. In women, sudden increases in abdominal pressure from actions such as coughing, sneezing, and laughing can result in loss of bladder control.1,2,6,7 Varying degrees of urinary incontinence have been reported in dogs with USMI. Most owners report leakage of urine when the dog is recumbent or sleeping. Increased periods of incontinence have also been reported in dogs after strenuous exercise, excitement, and steroid administration. In our experience, swimming and eating snow can also lead to increased incontinence in dogs.

Diagnosis The diagnosis of USMI is established by ruling out structural and functional abnormalities of the urinary and reproductive systems in patients that are neurologically normal. Physical examination findings are frequently unremarkable. Specific examination of the vulva and perivulvar region is necessary to

Surgical Views is a collaborative series between the American College of Veterinary Surgeons (ACVS) and Compendium. Upcoming topics in this series include cystoscopy and cystoscopic stone removal, vacuumassisted wound closure, and conventional foreign object removal. All Surgical Views articles are peer-reviewed by ACVS diplomates. To locate a diplomate, ACVS has an online directory that includes practice setting, species emphasis, and research interests (acvs.org/VeterinaryProfessionals/FindaSurgeon).

assess vulvar conformation and degree of vulvar recession. Perivulvar dermatitis and hyperpigmentation of the perivulvar skin secondary to chronic incontinence are frequently noted in dogs with USMI. Cystocentesis to collect a urine sample for complete urinalysis and bacteriologic culture is a critical first step in the diagnosis and management of patients with urinary incontinence. Infection, inflammation, uroliths, or neoplasia of the lower urinary system can result in loss of continence. If a urinary tract infection exists, treatment with appropriate antibiotic therapy for 14 to 21 days, followed by reevaluation of a urine culture 5 to 7 days after the completion of antibiotic therapy, should precede other diagnostic procedures. Abdominal radiography may detect radio dense urinary calculi or caudal displacement of the urinary bladder into the pelvic canal. Contrast radiography (e.g., retrograde vaginocystography) and contrast-enhanced computed tomography can enable more specific evaluation of the vestibule, vagina, and lower urinary and reproductive structures, including detailed information regarding the location of the bladder neck, urethral length, ureteral size, location of ureteral orifices, bladder wall thickness or irregularity, and presence of small uroliths. Uroendoscopy is useful to evaluate the luminal surfaces of the lower urinary and reproductive systems under magnification.

QuickNotes Cystocentesis to collect a urine sample is a critical first step in the diagnosis and management of patients with urinary incontinence.

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The surgical procedures reported in the veterinary literature to improve USMI in small animal patients have all been adapted and modified from procedures performed on women with diagnosed stress incontinence.

FIGURE 1

Colposuspension

Illustration by Tim Voit

Description

Illustration of colposuspension. Cranial traction is applied to the bladder and uterine body remnant. The vagina is exposed on either side of the urethra immediately cranial to the pubis. Nonabsorbable monofilament sutures are placed between the prepubic tendon and the seromuscular layer of the vagina, positioning the bladder neck cranially into the abdomen.

QuickNotes Surgical treatment is typically reserved for patients in which appropriate medical management has failed or is not possible.

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Anatomic abnormalities such as ureteral ectopia, ureterocele, and structural defects of the trigone and urethra can be definitively diagnosed with this method of imaging. Specific diagnostic confirmation of USMI is made based on the results of urodynamic studies, including a urethral pressure profile and leak point pressure. Patients with USMI have a decreased MUCP and leak point pressure compared with continent dogs.6,7,11–13

Surgical Treatment of Urethral Sphincter Mechanism Incompetence

Colposuspension uses the placement of sutures between the vagina and the prepubic tendon to create urethral resistance to urine outflow. This procedure results in cranial advancement and repositioning of the bladder neck and proximal urethra, exposing these structures to intraabdominal pressure. In addition, the urethra, cradled by the vagina, is positioned over the edge of the pelvic brim, which applies additional external compression (Figure 1). Colposuspension is the surgical procedure most commonly performed to treat spayed dogs with USMI. Colposuspension alone was reported to be curative in approximately 50% of patients; in approximately 40% of the remaining patients, continence was improved.1,2,6–8 A recent study evaluated the immediate urodynamic response to colposuspension in normal beagles.6 Leak point pressures were significantly increased, while MUCPs were decreased. Urethral length was assessed using measurements from vaginourethrograms and urethral pressure profiles and was determined to be slightly increased based on evaluation of lateral radiographs. Urodynamic studies indicated that the total profile length and the functional profile length were significantly increased.6 The long-term effects of colposuspension also have been examined in female dogs with USMI.7 Two months after colposuspension, 12 of 22 female dogs achieved complete continence. However, only three dogs remained completely continent 12 months after surgery. When medical therapy was instituted after surgery, an additional eight dogs regained complete urinary continence and nine were improved.7

Medical therapy (Box 1) is the first line of treatment for dogs with USMI. Surgical treatment of USMI is typically reserved for patients in which appropriate medical management has failed, that have adverse reactions to recommended medications, or that have medical conditions precluding the use of medical therapies. The goal of surgical treatment of USMI is to increase urethral resistance to the outflow of urine. To accomplish this, surgical procedures focus on correcting caudal displacement of the bladder neck to (1) increase intraabdominal forces and provide improved MUCP within the urethra (colposuspension, urethropexy, and urethral Technique lengthening), (2) increase urethral resistance With the patient in dorsal recumbency, clip and by reducing the diameter of the urethral aseptically prepare the ventral abdomen from lumen (urethropexy and submucosal collagen the xyphoid over the pubis, including the peri implants), and (3) improve functional urethral vulvar region. Aseptically pass an appropriatelength (colposuspension, urethral lengthening). size balloon-tip urethral catheter transurethrally

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into the bladder. Perform a caudal midline celiotomy from the umbilicus, extending over the cranial aspect of the pubis, and identify and isolate the insertion of the rectus abdominis muscles and prepubic tendon (Figure 2). Expose the bladder, proximal urethra, and uterus or uterine body remnant. If the patient is intact, OVH is performed at this point. Place a stay suture through the apex of the bladder for traction and manipulation and an Allis tissue forceps on the uterine body remnant for cranial traction. A peritoneal reflection forming the vesicogenital pouch exists between the dorsal aspect of the pelvic urethra and the ventral aspect of the vagina, tethering these structures together (Figure 3). This intimate anatomic association allows cranial traction of the uterine body remnant and vagina to result in cranial movement of the bladder neck and urethra. With cranial traction applied to the bladder and uterine body remnant, use a curved mosquito hemostat or right-angled forceps to bluntly dissect a small window through the periurethral fascia along each side of the urethra immediately cranial to the pubic brim, exposing the vagina dorsal to the urethra (Figure 4). Take care to avoid excessive dissection and disruption of the neurovascular supply to the vagina and urethra, positioned dorsolaterally within the pelvic canal. Identify the lateral wall of the vagina and grasp it with atraumatic forceps positioned on each side of the urethra. Based on the size of the patient, pre-place one or two 2-0 nonabsorbable monofilament sutures through the seromuscular layer of the vaginal wall on each side of the urethra and through the prepubic tendon, entering and exiting lateral to the insertion of the rectus abdominis muscle (Figure 5). Firm cranial traction on both the bladder and uterine remnant is needed to achieve cranial positioning while these sutures are tied on either side of the urethra. Insert a mosquito hemostat between the ventral aspect of the urethra and the pelvic brim to ensure that the urethra is not completely obstructed (Figure 6). Close the abdomen in a routine manner.

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Postoperative Care A urethral catheter with a closed urinary collection system should be maintained for 24 hours after surgery. Transient dysuria and stranguria due to urethral inflammation and partial urethral obstruction can occur after catheter removal. Complete urethral obstruction after colposuspension is rare. If complete urethral obstruction occurs, replacement of the urethral catheter for an additional 24 to 36 hours and administration of an NSAID are indicated. Attempts to manually express Compendium: Continuing Education for Veterinarians®

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Medical Management of Urethral Sphincter Mechanism Incompetence in Female Dogs Urethral sphincter mechanism incompetence (USMI) may be fully, partially, or transiently responsive to medical management.

QuickNotes Medical therapy is the first line of treatment for dogs with urethral sphincter mechanism incompetence.

α-Adrenergic Agonists Phenylpropanolamine (PPA; 1.0 to 1.5 mg/kg PO bid to tid) effectively controls incontinence in approximately 74% to 92% of dogs with USMI by stimulating α-adrenergic receptors in the urethra, increasing urethral tone. Many patients that are not completely continent following administration of PPA have improved continence.1,2,11–13,a In one study, more than half of the dogs that failed to respond when treated with the standard formulation of PPA became continent when treated with a sustained-release formulation (75-mg capsules; dose based on body weight).a The ability of PPA to control USMI decreases over time in some dogs. Not all α-adrenergic agonists are as effective as PPA in controlling incontinence. A recent study showed PPA to be more effective than pseudoephedrine.13 Minimal adverse effects (restlessness, mild behavioral changes) associated with PPA administration have been reported in some dogs. Dogs with systemic hypertension or clinically relevant cardiac or renal disease should not be treated with α-adrenergic agonists.11–13,a Estrogens Estrogens have also been shown to be effective in controlling USMI by increasing the number or sensitivity of α-adrenergic receptors in the urethra. Estrogens may have other, less well understood effects, including increased urethral tone arising from vascular changes and reduction in circulating concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).1–4,11,b Estriol increases urethral resistance in sexually intact and spayed female dogs without urinary incontinence.

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Estrogen therapy alone improves incontinence resulting from USMI in approximately 65% to 83% of treated dogs.1,2,b Diethylstilbestrol (DES; 0.5 to 1.0 mg/dog [0.02 mg/kg]), which is available from veterinary compounding pharmacies, is often effective in reducing incontinence attributed to USMI. A maximal induction dose of 1 mg/dog is given for 3 to 7 days; the dose is then decreased to every other day and then to the lowest dose that will maintain continence. Some dogs cannot tolerate DES at the doses required to maintain continence without manifesting clinical signs of estrus. Conjugated estrogens such as Premarin (Wyeth Pharmaceuticals, Philadelphia) are more readily available than DES and can be administered at 20 μg/kg every 4 days as an alternative therapy. Bone marrow toxicity is a potential adverse effect of estrogen therapy, but treatment with low doses of DES or conjugated estrogens appears to be safe. Intermittent low-dose maintenance with DES or conjugated estrogen to control incontinence may be preferred by owners over multiple daily doses of PPA, despite the fact that PPA is often more effective. In some patients with refractory incontinence, DES can be administered simultaneously with PPA to achieve a synergistic response that may effectively control incontinence. Other Therapies Detrusor instability or hyperactive bladder may contribute to incontinence in some dogs with USMI. A therapeutic trial with anticholinergic agonists (e.g., oxybutynin, flavoxate) to relax spasms of the detrusor muscle may be warranted. Oxybutynin (0.2 mg/kg PO q8–12h) and flavoxate (100 to 200 mg PO q8h) have been effective in the treatment of potential detrusor instability in dogs.

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Box 1

Treatment with gonadotropin-releasing hormone (GnRH) analogues was recently reported to result in complete continence in more than half of dogs with USMI in which traditional medical therapies failed.c,d An average of 253 days of continence was observed in seven dogs that became fully continent with a GnRH analogue as the sole treatment. An additional five dogs that had partial improvement with GnRH analogue treatment became fully continent when PPA was also administered. Treatment with GnRH analogues reduces the concentrations of FSH and LH that develop after OVH in dogs.e Increased concentrations of FSH and LH may play a role in development of USMI in susceptible dogs. However, MUCP does not appear to be directly related to circulating concentrations of FSH or LH.e Treatment with leuprolide, a GnRH analogue, did not increase MUCP in dogs with USMI that regained urinary continence.c,d Receptors for GnRH, FSH, and LH have been demonstrated in various regions and densities in the canine urethra and bladder. With a success rate of 71%, long-acting GnRH analogues are effective as a first-line treatment for USMI, but this rate is lower than that achieved with PPA.

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Bacon NJ, Oni O, White RAS. Treatment of urethral sphincter mechanism incompetence in 11 bitches with a sustained-release formulation of phenylpropanolamine hydrochloride. Vet Rec 2002;151(13):373-376. b Angioletti A, DeFrancesco I, Vergottini M, Battocchio ML. Urinary incontinence after spaying in the bitch: incidence and oestrogen-therapy. Vet Res Commun 2004;28(Suppl 1):153-155. c Reichler IM, Jöchle W, Piché CA, et al. Effect of long acting GnRH analog or placebo on plasma LH/FSH, urethral pressure profiles and clinical signs of urinary incontinence due to sphincter mechanism incompetence in bitches. Theriogenology 2006;66(5):1227-1236. d Reichler IM, Barth A, Piché CA, et al. Urodynamic parameters and plasma LH/FSH in spayed beagle bitches before and 8 weeks after GnRH depot analogue treatment. Theriogenology 2006;66:2127-2136. e Reichler IM, Pfeiffer E, Piché CA, et al. Changes in plasma gonadotropin concentration and urethral closure pressure in the bitch during the 12 months following ovariectomy. Theriogenology 2004;62(8):1391-1402. a

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FIGURE 2

FIGURE 3

QuickNotes Colposuspension is the surgical procedure most commonly performed to treat spayed dogs with urethral sphincter mechanism incompetence.

Surgical exposure of bladder and urethra for colposuspension. The abdominal incision extends over the pubis, exposing the insertion of the rectus abdominis muscle and prepubic tendon (arrows). FIGURE 4

Dissection of the periurethral fascia on either side of the urethra immediately cranial to the pubis exposes the dorsally positioned vagina.

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The bladder is reflected caudally, demonstrating the vesicovaginal fold (arrow) between the dorsal aspect of the urethra and the vagina. Cranial traction of the vagina facilitates repositioning of the bladder neck cranially into the abdomen. FIGURE 5

Placement of colposuspension sutures. Nonabsorbable monofilament sutures are pre-placed between the prepubic tendon and the seromuscular layer of the vagina on either side of the urethra.

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the bladder to void its contents may cause patient discomfort. Persistent complete urethral obstruction that does not respond to appropriate conservative treatment over a period of 3 to 5 days after surgery may require removal of the colposuspension sutures between the vaginal wall and prepubic tendon.

Inspired by Need.

Urethropexy

Description

Urethropexy is an alternative to colposuspension that is aimed at restoring the bladder neck and proximal urethra to an intraabdominal position while simultaneously increasing resistance to urine flow by reducing the diameter of the urethral lumen.14,15 Cystourethropexy was initially reported in 10 female dogs diagnosed with USMI and pelvic bladder. The results of surgery alone were considered excellent in two dogs, and urethropexy combined with medical therapy (phenylpropanolamine [PPA]) resulted in marked improvement in an additional six dogs. One dog did not improve with surgery.14 A later study reported the results of treatment of 100 female dogs with urethropexy for incontinence due to USMI.15 Surgery alone led to complete control of incontinence in 56 dogs and improvement of continence in 27 dogs. Of the other 17 dogs, nine failed to respond and eight showed initial improvement but later relapsed. Nine of these 17 dogs underwent a second urethropexy procedure, resulting in complete continence in six dogs and improvement in three. Postoperative complications were observed in 21 dogs, including increased frequency of urination (14 dogs), dysuria (six), and anuria (three).15 As with other procedures intended to increase tension within the urethral wall, transient or persistent dysuria as a result of partial urethral obstruction and failure to improve continence were the most common complications noted in both studies.14,15

Technique Position the patient in dorsal recumbency and clip and aseptically prepare the ventral abdomen. Perform a caudal midline celiotomy from the umbilicus, extending over the cranial aspect of the pubis. Expose the bladder, urethra, and uterine body remnant and place a stay suture through the apex of the bladder for cranial traction. Using blunt dissection, clear the periurethral fat from the ventral aspect of the bladder neck and pelvic urethra. Pre-place six to 10 horizontal mattress sutures bilaterally using a 2-0 nonabsorbable monofilament suture material. The sutures should enter the abdominal cavity, passing full thickness through the ventral abdominal wall, including the rectus fascia. They should Compendium: Continuing Education for Veterinarians®

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FIGURE 6

to pass a urethral catheter after surgery may be difficult and traumatic to the surgical site within the urethra and should be avoided if at all possible. Administration of an NSAID for 7 to 10 days after surgery is indicated to reduce discomfort and soft tissue swelling.

Urethral Lengthening

Description

Cranial traction is applied to the uterine body remnant while the pre-placed sutures are tied to complete the colposuspension. A mosquito hemostat is gently inserted between the pubis and the urethra to ensure that the urethra is not completely obstructed.

QuickNotes A significantly short urethra prohibits cranial movement of the bladder neck into the abdominal cavity, eliminating the ability to use some surgical procedures.

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Urethral lengthening has been used to treat congenital USMI in cats and dogs with a notably shortened urethra resulting in pelvic displacement of the bladder neck. A significantly short urethra (urethral hypoplasia) prohibits cranial movement of the bladder neck into the abdominal cavity, eliminating the ability to use surgical procedures such as colposuspension, urethropexy, and urethral slings to treat USMI. Reconstruction of the bladder neck and the use of ventrally based bladder tube flaps have been reported to taper the bladder neck, thereby elongating the proximal urethra. Excellent or good results were reported in seven of eight cats treated with this technique, and a good outcome was described in one dog.16,17 Urethral lengthening using bladder wall flaps has also been described for treatment of urinary incontinence in people. This technique may warrant further consideration with expanded clinical evaluation for the treatment of USMI in small animals with pelvic bladder.

then pass through the seromuscular layer of the urethra in a horizontal mattress pattern at either the nine or three o’clock position in the transverse section without penetrating the urethral lumen. The sutures then exit from the abdominal cavity through the abdominal wall, Technique including the rectus fascia, on the same side Position the patient in dorsal recumbency and (Figure 7). The two most caudal sutures on clip and aseptically prepare the ventral abdoeither side of the urethra are engaged through men. Perform a caudal midline celiotomy from the prepubic tendon as they enter and exit the umbilicus, extending over the cranial aspect the abdomen. Tighten and tie the pre-placed of the pubis. Expose the bladder, urethra, and sutures from caudal to cranial on each side of uterine body remnant. Make a ventral cystothe urethra. Close the abdomen routinely.14,15 tomy incision, extending into the proximal urethra, and create two V-shaped flaps in the Postoperative Care ventral aspect of the ventral bladder wall, using Some degree of stranguria and dysuria will the caudal extent of the incision in the proximal occur after surgery due to the increased outflow urethra as the point of both V flaps (Figure 8). resistance created within the urethral lumen. The widest portion of each V flap is located at Stranguria may persist for several weeks after the level of the ureteral orifices, at the tip of surgery. The patient’s voiding patterns should the trigone. Use 4-0 monofilament absorbable be observed daily for the first few days after sutures in a continuous or interrupted pattern surgery to be sure a small stream of urine is to primarily close the linear defect created in passed with each voiding effort. Complete the ventral wall of the bladder neck and proxiurethral obstruction is uncommon. Attempts mal urethra, thereby decreasing the diameter of

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the bladder neck lumen and elongating the proximal urethra. The initial descriptions of this procedure recommended suturing the bladder flaps to each other to prevent a loss in bladder capacity.17 Alternatively, resection of the bladder flaps makes the surgical procedure and closure much simpler, and the resultant loss of bladder capacity is usually inconsequential. Due to the tremendous regenerative capacity of the bladder, presurgical vesicular capacity is restored within a few weeks to months after surgery.

Postoperative Care Increased frequency of urination and stranguria are the most commonly anticipated adverse effects after reconstructive procedures to lengthen the urethra. Stranguria may be noted for several weeks. Avoid placement of a urethral catheter unless complete urethral obstruction occurs. Intermittent cystocentesis can be performed over a 24- to 36-hour period, and administration of an NSAID is indicated to reduce soft tissue inflammation of the lower urinary tract. Acepromazine administered at a low dose (0.01 to 0.025 mg/kg SC, IM, or IV q8h) may help relax the urethra, reducing stranguria and facilitating urine flow.

Urethral Slings

Description

Urethral sling procedures using seromuscular flaps created from the bladder wall or a synthetic material passed transpelvically through the obturator foramen have been combined with colposuspension to provide additional external compression of the pelvic urethra, increasing resistance to urine flow.18,19 These procedures are technically more difficult to perform. The reported outcomes are similar to those of colposuspension alone. It remains unclear whether there is an advantage to the use of a combined procedure.18 The modified sling urethroplasty procedure creates external compression at the vesicourethral junction by wrapping two seromuscular flaps created from the bladder neck region around the proximal urethra to increase resistance to urine flow.19

Technique Perform a colposuspension as previously described. Following colposuspension, make a 2- to 2.5-cm ventral midline incision through the seromuscular layer of the bladder neck, extending to the junction of the proximal urethra. Raise two rectangular seromuscular pedicle flaps with a caudal base from the ventral surface of the bladder neck region (Figure 9). These flaps should be between 4 and 10 mm in width, depending on the size of the patient. Place a 4-0 absorbable monofilament stay suture through the free end of each flap. Pass the flaps around each side of the proximal urethra and secure them on the dorsal aspect to provide compression at the vesicourethral junction.19 Primarily close the remaining seromuscular defect on the ventral bladder neck with a simple continuous or interrupted pattern using 4-0 absorbable monofilament sutures. Remove the urethral catheter to permit complete closure of this defect. If necessary, additional sutures can be placed dorsally in the sutured flaps to adjust the tension of the sling. Compression provided by the sling should be such that gentle digital pressure on the bladder is necessary to exceed the urethral pressure that permits urine flow.19 Close the abdomen in a routine manner.

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Minimally Invasive Urethral Bulking

Collagen Injection Technique Position the patient in right lateral recumbency under general anesthesia. Clip and aseptically prepare the vulva and perivulvar region. A 19or 14-French rigid cystoscope with a 30° angle is used for uroendoscopy and the injection procedure. Endoscopy is performed using a sterile fluid infusion to create a clear visual

Illustration of urethropexy procedure. Six to 10 sutures are pre-placed bilaterally between the body wall incision and the seromuscular layer of the urethra in a horizontal mattress pattern at either the three or nine o’clock position when viewed transversely. The most caudal sutures on either side engage the prepubic tendon as they enter and exit the abdomen. FIGURE 8

Illustration by Tim Voit

If the results of medical or surgical treatment of USMI are incomplete or unsatisfactory, endoscopic submucosal implantation of urethral bulking agents such as polytetrafluoroethylene (Teflon) or medical-grade collagen can be performed to create intraluminal resistance to urine outflow.20–22 Successful urethral bulking with submucosal collagen has been reported in women and dogs.21,22 Collagen products are commonly used in people to correct defects of the skin and soft tissues. A specific collagen product for urologic use (Contingen, Bard Urological, Covington, GA) has been commercially developed and approved for use in humans. This product is composed of highly purified bovine dermal collagen that is cross-linked with glutaraldehyde and dispersed in phosphate-buffered saline. The collagen component is composed of approximately 95% type I collagen and 5% or less type III collagen. This product is packaged in a sterile 2.5-mL syringe for single use. Collagen has a higher degree of biocompatibility compared with other products previously reported for urethral bulking (e.g., polytetrafluoroethylene). Initial reports showed a control rate (complete continence) of 53% for USMI treated with one or two series of submucosal injections of collagen. This rate improved to 75% when PPA was administered to dogs in which collagen injections provided inadequate urinary control.21 More recently, a success rate of 68% was reported in 40 female dogs with USMI treated with submucosal collagen injections.22 Some dogs may require a second series of collagen injections if incontinence is uncontrolled or relapses. Repeat injection procedures are usually easier to complete because the previous urethral bulking site is readily identified and augmented.

Illustration by Tim Voit

FIGURE 7

Description

Illustration of urethral lengthening using the bladder-flap reconstruction technique. A midline cystotomy incision is made extending to the proximal urethra. Two V-shaped full-thickness flaps are created in the ventral bladder wall (dashed lines). The point of each V is the caudal extent of the incision in the proximal urethra. The widest portion is at the level of the ureteral orifices. The flaps can be excised with little consequence to bladder capacity. Primary closure of the linear incision in the ventral wall of the bladder neck and proximal urethra reduces the luminal diameter of the bladder neck, thereby elongating the proximal urethra.

field. Mucosal hemorrhage can be controlled with the infusion of cold fluids. An assistant with sterile gloves should prepare the collagen and injection device. Perform a complete evaluation of the lower urinary and reproductive structures to rule out anatomic causes of urinary incontinence before injecting the collagen. Position the tip

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FIGURE 9

FIGURE 10

FIGURE 11

Endoscopic view of submucosal collagen injection. The injection needle is passed through the biopsy channel of the cystoscope and positioned immediately below the mucosal layer of the urethra distal to the vesicourethral junction.

Endoscopic view of completed submucosal collagen injections. Visual occlusion of the urethral lumen.

Illustration by Tim Voit

of the cystoscope within the proximal urethra to visualize the vesicourethral junction, and aseptically pass the injection device through the biopsy channel of the cystoscope until the beveled needle end is visible in the optical field. The recommended site for collagen injection is approximately 1.5 to 2 cm caudal to the vesicourethral junction. Position the cystoscope to facilitate insertion of the beveled tip of the injection device immediately below the urethral mucosa into the submucosal layer.

Slowly inject the collagen, watching for immediate elevation of the urethral mucosa to create a mounding effect (Figure 10). If the needle is positioned too deep, there is minimal to no intraluminal deformation of the urethral mucosa. The collagen is commonly injected at three to four sites in a circle. The amount of collagen injected at each site is determined visually. Injection of excessive collagen at any given site can result in mucosal disruption and leakage of collagen from the site. The procedure is considered complete when the injection sites appose one another, achieving visual obstruction of the urethral lumen (Figure 11). Patients should be continent immediately after this procedure. Dogs with moderate to severe inflammation or urinary tract infection may experience some minor incontinence until the infection/inflammation is resolved medically. If incontinence persists after the initial collagen injections, this procedure can be repeated, enhancing the previously injected sites. Administration of PPA has been shown to further enhance control of urinary continence after collagen injection. Complete urinary outflow obstruction has not been reported in dogs. Follow-up endoscopic examinations have uniformly demonstrated that the submucosal collagen deposits can remain visually unchanged for years. Relapse of incontinence after prolonged successful control with collagen injections may be related to absorption of the phosphate buffer component of the collagen preparation.

Illustration of the modified urethral sling procedure. A ventral midline incision is made through the seromuscular layer of the bladder neck and proximal urethra. Two rectangular seromuscular pedicle flaps are elevated from the ventral surface of the bladder neck region. The flaps are passed around each side of the vesicourethral junction and secured on the dorsal aspect, providing external compression of the bladder neck. Primary closure of the seromuscular defect on the ventral bladder neck tapers the bladder neck and elongates the proximal urethra.

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Future Directions in Treatment Recognizing that no medical or surgical treatments of female dogs with USMI have been uniformly successful, current investigations are focusing on the practical use of gonadotropin-releasing hormone analogues as a single therapy or in combination with other medical or surgical treatments (Box 1). In addition, work has begun to evaluate the efficacy of a percutaneously controlled static hydraulic urethral sphincter in dogs.23 This system consists of a doughnut-shaped silicone vascular occluder attached to a subcutaneous fluid injection port. The luminal diameter of the occluder can be adjusted by the infusion of small volumes of saline through the injection port. The occluder is surgically placed around the bladder neck to provide external compression, preventing passive urine outflow, and the degree of occlusion is adjusted until optimal

References

1. Gregory SP. Developments in the understanding of the pathophysiology of urethral sphincter mechanism incompetence in the bitch. Br Vet J 1994;150:135-150. 2. Holt PE. Importance of urethral length, bladder neck position and vestibulovaginal stenosis in sphincter mechanism incompetence in the incontinent bitch. Res Vet Science 1985;39:364-372. 3. McLoughlin MA. Management of urinary incontinence. Proc BSAVA Symp 2004. 4. Hoelzler MG, Lidbetter DA. Surgical management of urinary incontinence. Vet Clin North Am Small Anim Pract 2004 (34):1057-1073. 5. Stöcklin-Gautschi NM, Hässig M, Reichler IM, et al. The relationship of urinary incontinence to early spaying in bitches. J Reprod Fertil Suppl 2001:57:233-236. 6. Fowler JD, Rawlings CA, Mahaffey MB, et al. Immediate urodynamic and anatomic response to colposuspension in female beagles. Am J Vet Res 2000;61:1353-1357. 7. Rawlings CA, Barsanti JA, Mahaffey MB, Bement S. Evaluation of colposuspension for treatment of incontinence in spayed female dogs. JAVMA 2001;219(6):770-775. 8. Gregory SP, Holt PE. The immediate effect of colposuspension on resting and stressed urethral pressure profiles in anesthetized incontinent bitches. Vet Surg 1994;23:330-340. 9. Mahaffey MB, Barsanti JA, Barber DL, Crowell WA. Pelvic bladder in dogs without urinary incontinence. JAVMA 1984;184(12): 1477-1479. 10. Adams WM, DiBartola SP. Radiographic and clinical features of pelvic bladder in the dog. JAVMA 1983;182(11):1212-1217. 11. Rosen AE, Ross L. Diagnosis and pharmacological management of disorders of urinary incontinence in the dog. Compend Cont Educ Pract Vet 1981;3:601-610. 12. Richter KP, Ling GV. Clinical response and urethral pressure profile changes after phenylpropanolamine in dogs with primary sphincter mechanism incompetence. JAVMA 1985;187:605-611. 13. Byron JK, March PA, Chew DJ, DiBartola SP. Effect of phenylpropanolamine and pseudoephedrine on the urethral pressure profile and continence scores of incontinent female dogs. J Vet Intern Med 2007;21(1):47-53.

control (i.e., the patient can void urine without obstruction and retain urine without incontinence) is achieved.23

Conclusion Surgical treatment of USMI is focused on dogs in which appropriate medical therapies have failed or medical conditions prevent the use of medical treatment. Surgery or minimally invasive procedures such as collagen implantation may provide further control of continence in some difficult cases.

SURGICAL VIDEO

To see a video of collagen injection, visit CompendiumVet.com.

14. Massat BJ, Gregory CR, Ling GV, et al. Cystourethropexy to correct refractory urinary incontinence due to urethral sphincter mechanism incompetence preliminary results in ten bitches. Vet Surg 1993;22(4):260-268. 15. White RN. Urethropexy for the management of urethral sphincter mechanism incompetence in the bitch. J Small Anim Pract 2001;42:481-486. 16. Holt PE. Surgical management of congenital urethral sphincter mechanism incompetence in eight female cats and a bitch. Vet Surg 1993;22(2):98-104. 17. Fowler JD, Holmberg DL. Proximal urethral reconstruction using a distally based bladder tube flap an experimental study. Vet Surg 1987;16(2):139-145. 18. Muir P, Goldsmid SE, Bellenger CR. Management of urinary incontinence in five bitches with incompetence of the urethral sphincter mechanism by colposuspension and a modified sling urethroplasty. Vet Rec 1994;34:38-41. 19. Nickel RF, Wiegand U, Van Den Brom WE. Evaluation of a transpelvic sling procedure with and without colposuspension for treatment of female dogs with refractory urethral sphincter mechanism incompetence. Vet Surg 1998;27:94-104. 20. Arnold S, Jaeger P, DiBartola S, et al. Treatment of urinary incontinence in dogs by endoscopic injection of Teflon. JAVMA 1989;195:1369-1374. 21. Arnold S, Hubler M, Lott-Stolz G, Rusch P. Treatment of urinary incontinence in bitches by endoscopic injection of glutaraldehyde cross-linked collagen. J Small Anim Pract 1996;37:163-168. 22. Barth A, Reichler IM, Hubler M, et al. Evaluation of long-term effects of endoscopic injection of collagen into the urethral submucosa for treatment of urethral sphincter incompetence in female dogs: 40 cases (1993-2000). JAVMA 2005;226(1):73-76. 23. Adin CA, Farese JP, Cross AR, et al. Urodynamic effects of a percutaneously controlled static hydraulic urethral sphincter in canine cadavers. Am J Vet Res 2004;65(3):283-288.

CompendiumVet.com | August 2009 | Compendium: Continuing Education for Veterinarians®

373

Section Namee

At a Glance Risk Factors for Gastric Dilatation–Volvulus Page 60

Overview of the Veress Needle and Hasson Technique for Obtaining Abdominal Access Page 60

Laparoscopic-Assisted Gastropexy Page 61

Laparoscopic Gastropexy Page 63

Dr. Rawlings discloses that he has received ﬁnancial support from Biovision, Covidien, Ellman International, Endoscopic Support Services, and Karl Storz Veterinary Endoscopy.

Laparoscopic-Assisted and Laparoscopic Prophylactic Gastropexy: Indications and Techniques ❯❯ Jeffrey J. Runge, DVM University of Pennsylvania

❯❯ Philipp Mayhew, BVM&S, MRCVS, DACVS Columbia River Veterinary Specialists Vancouver, Washington

❯❯ Clarence A. Rawlings, DVM, PhD, DACVSa The University of Georgia

astric dilatation–volvulus (GDV) is open surgical gastropexy techniques have a syndrome characterized by rapid been described: tube, circumcostal, belt accumulation of gas or food in the loop, muscular ﬂap, gastrocolopexy, and stomach, increased intragastric pressure incisional. Because of the high mortality and wall tension, and rotation of the rate associated with the development of stomach about its long axis. Gastric dis- GDV, these procedures may be used protention unleashes a series of potentially phylactically in dogs that have not had GDV lethal pathophysiologic events, the most but are considered to be at high risk.8,9 important of which are compression of Studies have indicated that a prophylacthe portal and caudal vena caval venous tic gastropexy can result in a twofold to blood ﬂow, gastric necrosis, tissue aci- 30-fold reduction in lifetime mortality assodosis, cardiac arrhythmia, disseminated ciated with GDV for rottweilers and Great intravascular coagulation, and hypoten- Danes, respectively.10 sive and cardiogenic shock.1 For dogs Recent advances in veterinary medicine that develop GDV, surgical correction have included a move toward more miniis strongly recommended. Among those dogs, mortality remains high (15% to TO LEARN MORE 33%), even with aggressive resuscitative management.2–5 A gastropexy is the creation of a permanent adhesion between the gastric antrum and the adjacent right body wall. Failure to perform a gastropexy at the time of surgery for GDV correction results in a >50% recurrence rate,4 whereas performing a prophylactic gastropexy during corrective surgery for GDV decreases the recurrence rate by 4% to 10%.4,6,7 As a result, gastropexy is now considered the standard of care.4 Several

Compendium: Continuing Education for Veterinarians® | February 2009 | CompendiumVet.com

For a detailed description of abdominal access using a Veress needle or the Hasson technique, see the August 2008 Surgical Views article, “Canine Laparoscopic and LaparoscopicAssisted Ovariohysterectomy and Ovariectomy.” This article is available at CompendiumVet.com.

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1/16/09

10:24 AM

Page 1

What do dogs who take VETORYL (trilostane) have in common? ®

Results like these.

Prior to VETO RYL treatment

Effective treatment for Cushing’s syndrome is now FDA approved. You now have easy access to the most powerful ^LHWVU PU [OL ÄNO[ HNHPUZ[ JHUPUL *\ZOPUN»Z syndrome. VETORYL Capsules are the only licensed treatment available for both pituitary-dependent and adrenal-dependent hyperadrenocorticism.

treatment Following 3 months of with VETORYL

Following 9 months of treatment with VETO RYL

(trilostane)

Photographs courtesy of Carlos Melian, DVM, PhD

VETORYL is a trademark of Dechra Ltd. ©2009, Dechra Ltd. NADA 141-291, Approved by FDA (Z ^P[O HSS KY\NZ ZPKL LMMLJ[Z TH` VJJ\Y 0U ÄLSK Z[\KPLZ [OL TVZ[ JVTTVU ZPKL LMMLJ[Z YLWVY[LK ^LYL WVVY YLK\JLK HWWL[P[L ]VTP[PUN SL[OHYN` diarrhea, and weakness. Occasionally, more serious side effects, including severe depression, hemorrhagic diarrhea, collapse, hypoadrenocortical crisis, VY HKYLUHS ULJYVZPZ Y\W[\YL TH` VJJ\Y HUK TH` YLZ\S[ PU KLH[O =,;69@3 *HWZ\SLZ HYL UV[ MVY \ZL PU KVNZ ^P[O WYPTHY` OLWH[PJ VY YLUHS KPZLHZL or in pregnant dogs. Refer to the prescribing information for complete details or visit www.VETORYL.com. VTYL0209-01-47122-CPD

See Page 60 for Product Information Summary

VETORYL Capsules (trilostane) ®

30 mg and 60 mg strengths Adrenocortical suppressant for oral use in dogs only

QuickNotes Predisposition to GDV has been demonstrated for several breeds.

HUMAN WARNINGS: Keep out of reach of children. Not for human use. Wash hands after use. Do not empty capsule contents and do not attempt to divide the capsules. Do not handle the capsules if pregnant or if trying to conceive. Trilostane is associated with teratogenic effects and early pregnancy loss in laboratory animals. In the event of accidental ingestion/overdose, seek medical advice immediately and take the labeled container with you. PRECAUTIONS: Hypoadrenocorticism can develop at any dose of VETORYL Capsules. A small percentage of dogs may develop corticosteroid withdrawal syndrome within 10 days of starting treatment. Mitotane (o,p’-DDD) treatment will reduce adrenal function. Experience in foreign markets suggests that when mitotane therapy is stopped, an interval of at least one month should elapse before the introduction of VETORYL Capsules. The use of VETORYL Capsules will not affect the adrenal tumor itself. Adrenalectomy should be considered as an option for cases that are good surgical candidates. ADVERSE REACTIONS: The most common adverse reactions reported are poor/reduced appetite, vomiting, lethargy/dullness, diarrhea, and weakness. Occasionally, more serious reactions including severe depression, hemorrhagic diarrhea, collapse, hypoadrenocortical crisis, or adrenal necrosis/rupture may occur, and may result in death.

mally invasive procedures, and the use of laparoscopic surgery for creating a less invasive prophylactic gastropexy has been investigated. These techniques can be performed in isolation or in conjunction with surgical sterilization. Laparoscopic-assisted,11 laparoscopic,12–14 and endoscopic15 gastropexy techniques have proven successful. The clinical outcome of a reported laparoscopic-assisted gastropexy16 indicated a persistent attachment between the stomach and the body wall with few complications and effective prophylaxis against GDV development. Studies reveal that an intracorporeally sutured laparoscopic gastropexy can be performed safely and effectively and has less impact on the dog’s postoperative activity level than a laparoscopic-assisted gastropexy.13 However, the adhesion strength and long-term outcome of the intracorporeally sutured laparoscopic technique have not yet been evaluated.13 In this article, we describe the techniques for laparoscopic-assisted and laparoscopic gastropexy.

Risk Factors for Gastric Dilatation–Volvulus A breed predisposition has been demonstrated for Great Danes, German shepherds, standard poodles, Weimaraners, Saint Bernards, Gordon setters, Irish setters, bassett hounds, Airedale terriers, Irish wolfhounds, borzois, bloodhounds, Akitas, and bull mastiffs.2,3 Large,

Overview of the Veress Needle and Hasson Technique for Obtaining Abdominal Access BOX 1

The Veress needle has a blunt-tipped, spring-loaded stylet within a sharp-tipped needle. As it is advanced through the body wall, the sharp tip penetrates the abdominal musculature; once within the peritoneal cavity, the spring-loaded protective stylet is deployed, thus minimizing risk of iatrogenic organ damage when the abdominal cavity is penetrated. Peritoneal insufﬂation can then be performed through the needle, followed by trocar placement. The Hasson technique uses a blunt cannula in a trocar–cannula assembly that is passed through a very small incision, usually created in a subumbilical location. Once the peritoneum has been sharply penetrated, the trocar–cannula assembly is advanced into the abdomen, pointing to the right side to minimize the risk of splenic laceration. If a 5-mm telescope and instrumentation are used, a 6-mm trocar–cannula assembly should be placed ﬁrst.

Compendium: Continuing Education for Veterinarians® | February 2009 | CompendiumVet.com

Laparoscopic-Assisted Gastropexy To perform a laparoscopic-assisted gastropexy, place the dog in dorsal recumbency and clip and aseptically prepare the abdomen from the xiphoid cartilage to the brim of the pubis. Abdominal access can be obtained by use of a Veress needle or the Hasson technique (BOX 1). If the Hasson technique is used, a blunt cannula must be employed for initial port placement. If a pneumoperitoneum has already been established through the use of a Veress needle, a sharp cannula can be used for this purpose. A pneumoperitoneum is usually established with carbon dioxide, using a mechanical insufflator that allows controlled insufflation and intraabdominal pressure monitoring. The intraabdominal pressure measured with the insufflator should not be allowed to exceed 10 to 15 mm Hg while the trocars are placed; it should then be reduced to 6 to 8 mm Hg, or just sufficient to maintain an optical space, during the laparoscopic portion of the gastropexy. Place a 0° or 30° 5-mm laparoscope through the subumbilical port, just lateral to the right margin of the rectus abdominus and 3 to 5 cm caudal to the last rib (FIGURE 1). The second trocar–

FIGURE 1

QuickNotes Dietary risk factors that can lead to the development of GDV include food characteristics and feeding practices or behaviors.

Patient positioned in dorsal recumbency. The camera port is placed on the midline just caudal to the umbilicus. The instrument port is placed just lateral to the right margin of the rectus abdominus and 3 to 5 cm caudal to the last rib. Courtesy of Clarence Rawlings, DVM, PhD, DACVS.

cannula assembly should be large enough to accommodate 10-mm instrumentation. Transilluminate the incision site to identify and avoid abdominal wall vessels. Nerves parallel vessels; thus, avoiding the vessels reduces the risk of hemorrhage and nerve injury. Pass a 10-mm laparoscopic Babcock or DuVall (FIGURE 2) forceps through the instrument port to manipulate the cranial abdominal organs and obtain an unobstructed view of the antrum of the stomach. Then grasp the FIGURE 2

10-mm DuVall laparoscopic forceps are useful for grasping the antrum of the stomach.

Courtesy of Clarence Rawlings.

mixed-breed dogs are also predisposed. Various non–breed-associated risk factors have been shown to be associated with GDV. Nondietary risk factors include lean body condition, older age, male sex, increased thoracic depth-to-width ratio, first-degree relative with GDV, aggressive or fearful temperament, histologic evidence of inflammatory bowel disease, and increased hepatogastric ligament length.15 Dietary risk factors that can lead to the development of GDV include food characteristics— small food particle size and the presence of oil or fat among the first four ingredients of a dry food—and feeding practices or behaviors, including feeding a large amount of food, once-daily feeding, feeding from an elevated bowl, eating quickly, and aerophagia.15 Based on these risk factors, it may be reasonable to conclude that certain canine subpopulations are at such a high risk of developing GDV that they could be considered good candidates to receive prophylactic treatment.

CompendiumVet.com | February 2009 | Compendium: Continuing Education for Veterinarians®

Section Name

FIGURE 3

The antrum of the stomach is grasped using 10-mm Babcock or DuVall forceps.

Courtesy of Clarence Rawlings.

FIGURE 4

antrum of the stomach with the forceps midway between the mesenteric and antimesenteric sides, approximately 5 to 7 cm oral to During antral exteriorization, take care to the pylorus (FIGURE 3). This is also the site for avoid twisting. Place stay sutures at either end of the proposed seromuscular incision in the stomincisional gastropexy. ach to aid in exposure. These stay sutures are later Once you have a firm hold on the antrum, removed before closure. evacuate the pneumoperitoneum. Exteriorize the forceps and antrum by removing the right- the mucosa to ensure that the sutures are not side cannula and extending the port incision to placed through the mucosa into the lumen 4 to 5 cm in an orientation parallel to the last and that adequate muscle tissue is exposed rib. During this dissection, use of a muscle- for the gastropexy. Place two simple, continusplitting approach to the external and internal ous lines of 2-0 or 0 synthetic, monofilament, abdominal oblique muscles by incising parallel absorbable suture to appose both margins of to the orientation of their fibers may result in the seromuscular layer in the antrum to the less postoperative pain. The transversus abdo- transversus abdominus muscle (FIGURE 6). Before closure, remove the full-thickness minis is the final layer to be sectioned before the stomach can be exteriorized. During the stay sutures. Close the oblique abdominal musantral exteriorization, take care to avoid twist- cles with interrupted or continuous sutures of ing. As soon as the stomach is visualized, place synthetic, absorbable material, and close the a full-thickness stay suture of 2-0 absorbable remainder of the incision in routine fashion. or nonabsorbable monofilament suture in the After completion, briefly reestablish the pneustomach wall. The forceps can be released at moperitoneum and view the gastropexy laparoscopically to ensure that this point. Place a second stay optimal positioning and orisuture 4 to 5 cm orally or aboSURGICAL entation have been achieved rally. The relative positions of VIDEO and that excessive hemorthese sutures define the extent rhage or body wall defects are of the proposed gastropexy not present (FIGURE 7). (FIGURE 4). To see a video of exteriorizaMake an incision at least 4 After once more evacuattion of the stomach wall, stay suture placement, and initial cm long through the seromusing the pneumoperitoneum, suturing of the seromuscular cular layer of the antrum along remove the midline canlayer of the stomach wall to the long axis of the stomach, nula and close the incision the transversus abdominis avoiding the larger blood ves(FIGURE 8). Closure of any muscle, visit the Web port-site incisions that are 5 sels emerging from the greater Exclusives section of mm or larger should include and lesser curvatures (FIGURE CompendiumVet.com. 5). Dissect this incision from body wall closure to avoid the

Compendium: Continuing Education for Veterinarians® | February 2009 | CompendiumVet.com

Section Name

An incision is made through the seromuscular layer (SM) of the antrum along the long axis of the stomach, exposing the underlying gastric mucosa (GM).

Courtesy of Clarence Rawlings.

FIGURE 6

Courtesy of Clarence Rawlings.

FIGURE 5

Placement of the two simple continuous suture lines through the seromuscular layer (SM) of the antral region of the stomach to the transversus abdominus (TA) muscle. (GM = gastric mucosa)

a laparoscopic hernia stapler to close the tunnel opening with three to six staples placed possibility of incisional herniation of abdomi- individually while apposing the tissues with nal viscera. a grasping instrument12; alternatively, a modiﬁcation of this method has been described in Laparoscopic Gastropexy which the imperforate stoma resulting from the Use of Intracorporeal Stapling Devices anastomosis of the two tunnels was closed Place the dog in dorsal recumbency, clip and with an intracorporeal simple interrupted aseptically prepare the abdomen, and estab- suture pattern of 2-0 or 3-0 nonabsorbable lish a pneumoperitoneum. Place three 10- to monofilament suture material.11 There are significant disadvantages to 12-mm cannulae in the caudal aspect of the right side of the abdomen. Hold the ventral an intracorporeally stapled gastropexy. aspect of the gastric antrum with laparoscopic Full-thickness perforation of the gastric grasping forceps and make a 2- by 5-cm sub- wall was seen in 14% of cases in one study.12 mucosal tunnel with laparoscopic Metzenbaum This complication could lead to contaminascissors and laparoscopic Kelly forceps, using tion and abscess formation. This technique both sharp and blunt dissection. Make a simi- can also be associated with prolonged surgical time.12 A fur ther lar-sized tunnel in the adjacent disadvantage relates to the right lateral abdominal wall SURGICAL significant cost of using disbetween the transverse and VIDEO posable stapling devices. internal abdominal oblique muscles caudal to the last rib. Use of Intracorporeal Insert a 35-mm gastrointestiTo see a video of the Suturing nal anastomosis laparoscopic incisions in the transversus In this totally laparoscopic stapler (Endo-GIA, Covidien abdominis and seromuscular tech nique, the gastropexy is Inc, Mansﬁeld, MA) into the layer of the stomach, visit the created using intracorporeal dissected tunnels and staWeb Exclusives section of suturing techniques alone, ple the stomach to the right CompendiumVet.com. which, while requiring relaabdominal wall. You can use

QuickNotes There are signiﬁcant disadvantages to an intracorporeally stapled gastropexy.

CompendiumVet.com | February 2009 | Compendium: Continuing Education for Veterinarians®

Section Name

FIGURE 8

The gastropexy site is viewed laparoscopically to confirm correct position without twisting and to rule out excessive hemorrhage and open defects in the body wall.

QuickNotes Intracorporeal suturing is more technically challenging than laparoscopic-assisted gastropexy.

Courtesy of Clarence Rawlings.

FIGURE 7

Postoperative view of the laparoscopic-assisted gastropexy site.

tively little disposable equipment, do require sion in the seromuscular layer of the stomach. some speciďŹ c instruments. Apart from routine These incisions should be 4 to 5 cm long and laparoscopic equipment, two laparoscopic be adjacent to each other in an orientation needle holders (Szabo-Berci 5-mm, 33-cm lap- parallel to the ventral midline (FIGURE 10). Introduce an approximately 30-cm length aroscopic parrot-jaw needle holders, Karl Storz Endoscopy) are needed to complete the sutur- of 2-0 polyglactin 910 suture on a curved or ski-type needle into the peritoneal cavity by ing successfully. Establish a camera port in a subumbilical passing the needle through the body wall adjalocation as previously described, then estab- cent to the gastropexy site. First, suture the lish two 6-mm instrument ports on midline, lateral wall of the incisions in the transversus one 3 to 4 cm caudal to the xiphoid process abdominis muscle and antrum using a simple and the other midway between the two other continuous pattern. While tying knots, evacuports and directly medial to the traditional site ate the pneumoperitoneum to decrease tension and ensure secure knots and tight suture for open gastropexy (FIGURE 9). Pass a length of 2-0 nylon suture on a lines. Once the lateral margins of the incision 38-mm reverse-cutting 3/8 -circle curved nee- have been sutured, introduce a second piece dle percutaneously at the intended site of of suture and suture the medial margins to the gastropexy, 2 to 3 cm caudal to the last complete the gastropexy. Once suturing is rib and 5 to 8 cm lateral to midline. Grasp complete, remove the stay suture. Close the the needle with a laparoscopic needle holder three midline ports in routine fashion after the within the peritoneal cavity and take a deep, pneumoperitoneum has been evacuated. full-thickness bite through the antrum of the This technique is more technically chalstomach. Then pass the suture back through lenging than laparoscopic-assisted gastropexy the abdominal wall adjacent to its previous and requires the use of some specialized point of entry. This stay suture equipment (i.e., the laparois used as a temporary anchor scopic needle holders). It is SURGICAL to appose the stomach to the more time consuming, but it VIDEO body wall during incising and may be associated with less suturing. postoperative discomfort To see a video of suturing Make the first incision in because it avoids the parameand knot tying using laparothe transversus abdominis dian incision used in the lapscopic needle holders, visit muscle using laparoscopic aroscopic-assisted technique the Web Exclusives section Metzenbaum scissors. Then and therefore reduces tissue of CompendiumVet.com. make a partial-thickness incitrauma.13

Compendium: Continuing Education for VeterinariansÂŽ | February 2009 | CompendiumVet.com

Section Name

Courtesy of Philipp Mayhew.

FIGURE 10

Courtesy of Philipp Mayhew, BVM&S, MRCVS, DACVS.

FIGURE 9

A partial-thickness incision made in the seromuscular layer of the stomach and the transversus abdominis.

are associated with less tissue trauma and postoperative pain than open celiotomy. All the techniques require the use of basic Positions of the three ports used for the laparoscopic equipment and some specialintracorporeally sutured laparoscopic gasized training. We would advise veterinartropexy technique. The most caudal port is in ians wishing to perform these techniques a subumbilical location and is initially used as the to seek further specialized training. In the camera port. Once the two instrument ports are created, the camera is moved to the middle port. case of the totally laparoscopic techniques, some experience with intracorporeal suturConclusion ing using simulators or cadavers is recomIt is generally accepted that all the laparo- mended before performing these procedures scopic techniques described in this article on client-owned animals.

References 1. Burrows CG, Ignaszewski A. Canine gastric dilation-volvulus. J Small Anim Pract 1990;31:495-501. 2. Brockman DJ, Washabau RJ, Drobatz KJ. Canine gastric dilatation/volvulus syndrome in a veterinary critical care unit: 295 cases (1986–1992). JAVMA 1995;207:460-464. 3. Glickman LT, Glickman NW, Pérez CM, et al. Analysis of risk factors for gastric dilatation and dilatation-volvulus in dogs. JAVMA 1994;204(9):1465-1471. 4. Glickman LT, Lantz GC, Schellenberg DB, Glickman NW. A prospective study of survival and recurrence following the acute gastric dilatation-volvulus syndrome in 136 dogs. JAAHA 1998;34(3):253-259. 5. Beck JJ, Staatz AJ, Pelsue DH, et al. Risk factors associated with short-term outcome and development of perioperative complications in dogs undergoing surgery because of gastric-dilatation-volvulus: 166 cases (1992-2003). JAVMA 2006;229:19341939. 6. Ellison GW. Gastric dilatation volvulus. Surgical prevention. Vet Clin North Am Small Anim Pract 1993;23(3):513-530. 7. Hosgood G. Gastric dilatation-volvulus in dogs. JAVMA 1994; 204(11):1742-1747. 8. MacCoy DM, Sykes GP, Hoffer RE, et al. A gastropexy technique for permanent ﬁxation of the pyloric antrum. JAAHA 1982;18:763-768. 9. Fallah AM, Lumb WV, Nelson AW, et al. Circumcostal gas-

tropexy in the dog: a preliminary study. Vet Surg 1982;11:9-12. 10. Ward MP, Patronek GJ, Glickman LT. Beneﬁts of prophylactic gastropexy for dogs at risk of gastric dilatation-volvulus. Prev Vet Med 2003;60(4):319-329. 11. Rawlings CA. Laparoscopic-assisted gastropexy. JAAHA 2002;38(1):15-19. 12. Sánchez-Margallo FM, Díaz-Güemes I, Usón-Gargallo J. Intracorporeal suture reinforcement during laparoscopic gastropexy in dogs. Vet Rec 2007;160(23):806-807. 13. Hardie RJ, Flanders JA, Schmidt P, et al. Biomechanical and histological evaluation of a laparoscopic stapled gastropexy technique in dogs. Vet Surg 1996;25(2):127-133. 14. Mayhew PD, Brown DC. Prospective evaluation of two intracorporeally sutured prophylactic laparoscopic gastropexy techniques compared to laparoscopic-assisted gastropexy in dogs. Vet Surg 2009; in press. 15. Dujowich M, Reimer SB. Evaluation of an endoscopically assisted gastropexy technique in dogs. JAVMA 2008;232(7):1025. 16. Rawlings CA, Mahaffey MB. Prospective evaluation of laparoscopic-assisted gastropexy in dogs susceptible to gastric dilatation. JAVMA 2002;221:1576-1581. 17. Raghavan M, Glickman NW, Glickman LT. The effect of ingredients in dry dog foods on the risk of gastric dilatation-volvulus in dogs. JAAHA 2006;42(1):28-36.

CompendiumVet.com | February 2009 | Compendium: Continuing Education for Veterinarians®

Techniques for Laparoscopic and LaparoscopicAssisted Biopsy of Abdominal Organs ❯❯ Philipp Mayhew, BVM&S, MRCVS, DACVS Columbia River Veterinary Specialists Vancouver, Washington

At a Glance Patient Preparation and Positioning Page 171

Abdominal Access and Port Positioning Page 171

Liver Biopsy Page 171

Kidney Biopsy Page 173

Gastrointestinal Biopsy Page 173

Pancreatic Biopsy Page 175

Clinical Pearls Page 176

170

Abstract: Multiorgan pathology is a common ﬁnding during the diagnostic work-up of complex medical diseases in small animals. Collection of cytologic or biopsy samples from several abdominal organs can give the clinician crucial information in guiding therapy. Although many modalities are available for sample collection, laparoscopic and laparoscopic-assisted techniques offer a minimally invasive approach for collection of high-quality biopsy samples from multiple organs during one anesthetic episode. This article discusses the laparoscopic approaches and techniques for multiorgan biopsy in cats and dogs.

iagnostic evaluation of many different disadvantages versus surgical biopsy techmedical conditions can be assisted by niques.4 Full-thickness intestinal biopsy obtaining biopsy samples from multiple samples cannot be harvested endoscopiabdominal organs. This sample collection has cally, and access to the lower small intestine is not possible with currently available traditionally been performed several ways. “Open” celiotomy has the advantage of endoscopic technology. Some studies allowing thorough inspection of, and easy have shown the limitations of endoscopiaccess to, all abdominal organs. However, it cally collected biopsy samples for diagnosis the most invasive technique, sometimes ing certain conditions (e.g., lymphoma).5,6 necessitating an incision from the xiphoid Flexible endoscopy does, however, have process to the pubis for access to the cranial the advantage of being an outpatient procedure, allowing direct visualization of and caudal abdominal structures. Ultrasound-guided ﬁne-needle aspiration mucosal lesions, and avoiding the reported or needle-core biopsy techniques can be 12% dehiscence rate of full-thickness surgiused for obtaining samples from the liver, cal biopsies.7 Laparoscopic procedures (performed pancreas, kidneys, and mesenteric lymph nodes.1–3 Ultrasound-guided techniques are entirely within the peritoneal cavity) and minimally invasive, but they require a skilled laparoscopic-assisted procedures (which use ultrasonographer, do not allow access to all laparoscopic manipulation to exteriorize organs areas of the peritoneal cavity, and have been for extraperitoneal surgery) can allow a thorshown to produce inferior samples in many ough evaluation of most abdominal organs. cases when compared with open surgical or It is not known whether laparoscopic exploration of the abdominal cavity can be as laparoscopic biopsy techniques.1–3 Flexible gastroscopy and small intestinal thorough as open exploration. However, endoscopy can be used for harvesting gas- almost all abdominal structures are visible tric and small intestinal biopsy samples.4–6 laparoscopically, and the success of laparoThese techniques have advantages and scopic exploration of the peritoneal cavity

Compendium: Continuing Education for Veterinarians® | April 2009 | CompendiumVet.com

is limited only by the patience of the surgeon. port position depends on which techniques For example, laparoscopic examination of the are to be performed. In most cases, multiple full length of the bowel is possible but time organs can be accessed through a small numconsuming. Another important variable to con- ber of common instrument ports or one small sider is the reliability of preoperative abdomi- “assist” incision (an incision 2 to 4 cm in length nal imaging. In most cases, when preoperative created by enlargement of a previously placed imaging has identified the location of focal instrument port for exteriorization of abdomilesions or when diffuse disease only is sus- nal organs). Before beginning the procedure, pected, the need for laparoscopic visualization the surgeon should decide the minimum comof all organs is debatable. bination of instrument ports that will provide Compared with open celiotomy, a laparo- access to all organs to be biopsied. Usually, scopic approach has been shown to result in less two or three instrument ports are adequate. postoperative pain8 and a faster return to normal activity9 and may result in fewer and less severe Liver Biopsy wound-healing complications. This article pre- Due to its fi xed location and friable nature, sents some of the technical aspects of harvesting the liver is biopsied using totally laparoscopic biopsy samples using laparoscopic or laparo- techniques. When multiple organ biopsy samscopic-assisted techniques. These techniques ples are needed, the liver sample should be allow clinicians to offer their clients a high like- taken first so that if laparoscopic-assisted prolihood that, similar to open surgery, they will cedures are subsequently performed through obtain high-quality diagnostic samples from larger port incisions, it will not be necessary all the necessary organs during one procedure, to reestablish the pneumoperitoneum for liver when such an approach is clinically indicated. biopsy at the end of the procedure. However, In choosing which diagnostic techniques reinsufflation may be recommended if the surto use, clinicians must balance the desire to geon wishes to confirm adequate hemostasis obtain high-quality biopsy samples from all before completing the surgery. It is wise to the organs in which pathology is suspected in consider performing a full coagulation profile the least invasive way possible against own- before laparoscopic liver biopsy. I place a preers’ financial constraints and tolerance for the tied loop ligature (described below) in animals with coagulopathy or when harvesting large risk of potential complications. samples, although the need or benefit of this Patient Preparation and Positioning practice has not been evaluated scientifically. For all of the techniques described below, the In most cases, when a liver biopsy is perpatient is placed in dorsal recumbency and formed in isolation for diffuse hepatopathy, a sinthe abdomen is liberally clipped from 2 inches gle instrument port suffices. The port is placed cranial to the xiphoid process to the pubis. under direct visualization in a paramedian Laterally, the patient is clipped to approximately the midabdomen level as for a tradiTO LEARN MORE tional open celiotomy. It is important that wide clipping and aseptic preparation be performed in the unlikely event that conversion to an Patient preparation and the Hasson and Veress open procedure becomes necessary. Lateral needle techniques are described in more detail recumbency can be used for access to certain in the August 2008 Surgical Views article, individual organs, but when examination or “Canine Laparoscopic and Laparoscopic-Assisted biopsy of multiple organs is desired, I prefer Ovariohysterectomy and dorsal recumbency and the use of a subumbiliOvariectomy,” available cal telescope port. at CompendiumVet.com.

Abdominal Access and Port Positioning A subumbilical telescope port can be placed using either the Hasson or the Veress needle technique.10 For the following procedures, instrument

QuickNotes Before beginning the procedure, the surgeon should decide the minimum combination of instrument ports that will provide access to all organs to be biopsied.

A video demonstrating the Hasson technique is also available at CompendiumVet.com.

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A needle-core biopsy needle has been placed percutaneously and is inserted into the renal cortex before being discharged. The advantage of the laparoscopic approach is the ability to monitor hemorrhage after withdrawal of the instrument.

QuickNotes In all cases, liver biopsy sites should be visualized until the surgeon is convinced that all hemorrhage has ceased before removing the telescope.

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FIGURE 2

Courtesy of Dr. Mayhew

Courtesy of Philipp Mayhew, BVM&S, MRCVS, DACVS

FIGURE 1

Placement of the wound retraction device produces a small, protected, circular access incision into the peritoneal cavity.

position in either the right or left cranial quad- site with a vessel-sealing device has been rant of the abdomen. Care should be taken not shown in some studies to reduce hemorrhage to place the cannula cranial to the last rib, which associated with the procedure.11,12 Several samples can be taken from multiple risks entering the thoracic cavity and could precipitate pneumothorax. A 6-mm trocarâ&#x20AC;&#x201C;cannula lobes. By passing the telescope caudally or craassembly can be placed to accommodate 5-mm nially around the falciform fat, access to both cup biopsy forceps. A second port can be placed right and left sides of the liver is possible. If the on the contralateral side if the surgeon plans to surgeon judges that excessive hemorrhage is use a hemostatic device (vessel-sealing device occurring after liver biopsy, a piece of gelatin or ligature) to harvest the sample. If a focal liver sponge or oxidized regenerated cellulose can lesion has been diagnosed from preoperative be passed through a port and manipulated into imaging, the instrument port should be placed position at the biopsy site to promote clot foron the side of the focal lesion. If other laparo- mation and hemostasis. In all cases, the biopsy scopic procedures are to be performed in addi- sites should be visualized until the surgeon tion to the liver biopsy, the instrument ports is convinced that all hemorrhage has ceased used for those procedures can usually be used before removing the telescope. If hemorrhage is of concern (e.g., in anito access the liver, thus minimizing the number mals with advanced hepatic failure, focal or of necessary ports. The simplest way to perform a liver biopsy is highly vascular lesions, or known coagulopaby using 5-mm laparoscopic cup biopsy forceps thies), it may be preferable to apply a pretied to harvest pieces of liver from the edge of a lobe. loop ligature or extracorporeally assembled The tissue is grasped and gently twisted until it loop ligature to ligate the tip of the lobe separates from the rest of the lobe. Care should before taking biopsy samples. This ligation decreases the chance of severe be taken during this process hemorrhage; however, a secto avoid tearing liver parenSURGICAL ond port must be placed for chyma by rough handling, VIDEO application of the ligature. A which can lead to excessive modiďŹ ed Roeder laparoscopic hemorrhage. Performed corTo see videos of a laparoscopic slipknot is used. The loop rectly, this technique has liver biopsy using a 5-mm is passed through the instrubeen shown to cause minimal laparoscopic cup forceps, a ment cannula either with the bleeding in healthy dogs and gelatin sponge, and a pretied plastic application device (for to yield good-quality tissue loop ligature, visit commercial pretied loop ligasamples.11,12 Coagulation of CompendiumVet.com. the periphery of the biopsy tures [e.g., Endoloop, Ethicon

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Endosurgery, Cincinnati, OH] ) or with a knot pusher (for self-assembled loop ligatures). It must then be manipulated into position around the tip of a liver lobe. A blunt probe can aid in elevating the liver lobe during loop positioning. When the loop is in position, it is tied by advancing the plastic application device or knot pusher (for self-assembled loops) against the modiﬁed Roeder knot until it securely ligates the blood vessels and bile ducts within the parenchyma. The liver tissue distal to the ligature can then be cut with endoscissors and withdrawn through a cannula, or multiple bites can be taken with laparoscopic cup biopsy forceps. If a large focal liver mass is to be biopsied, extreme care should be taken because these lesions are often very vascular. Consideration should be given to taking a needle-core biopsy sample under laparoscopic guidance before collecting larger samples to gauge the level of hemorrhage that will result. Otherwise, a loop ligature should be used to harvest the sample to reduce the risk of profuse hemorrhage. It may be advisable to use a specimen retrieval bag to remove larger samples. Extension of the port site may be needed to recover these samples.

from the kidney and ensure that hemostasis has been achieved before closure. I prefer to use an automatic spring-activated needle-core biopsy needle to decrease the possibility of inadvertent premature needle withdrawal from the parenchyma that can occur from excessive movement with manually activated Tru-Cut needles. Under direct visualization, the biopsy needle is guided into the parenchyma and directed to pass across the renal cortex to maximize the number of glomeruli recovered13 (FIGURE 1). The sample is taken by activating the biopsy needle, which is subsequently withdrawn from the peritoneal cavity to recover the sample. Usually, one to two samples are taken from one or both kidneys, depending on the nature of the pathology suspected. If the needle is placed too deeply into the medulla, fewer glomeruli may be recovered and there is a greater risk of hemorrhage from arcuate vessels.13 The laparoscopic technique using a 14-gauge needle has been shown to give superior-quality biopsy samples compared with ultrasonographic guidance of the same-size needle.2

Gastrointestinal Biopsy Kidney Biopsy

Biopsies of the small intestine are usually If a single kidney is to be biopsied, a needle- performed using a laparoscopic-assisted techcore biopsy technique is usually selected. nique. In humans, in which the small intestiTheoretically, no instrument port is required nal lumen is significantly larger, endoscopic for this technique because the biopsy needle stapling devices can be used to resect small can be passed percutaneously into the perito- antimesenteric sections of small intestine. This neal cavity in a location directly ventral and would likely result in excessive compromise of somewhat caudal to the kidney. However, it the luminal diameter in small animals and so is is helpful to have one instrument port avail- not practical in these patients. Exteriorization able for passage of a blunt probe that can of bowel segments through a small assist incihelp manipulate the kidney into position for sion, followed by standard small intestinal the biopsy and place pressure on the biopsy biopsy sample collection from the antimessite after needle withdrawal to minimize hem- enteric border, is usually the best technique in orrhage from the site. This instrument port dogs and cats. can be placed on the ventral A technique for laparomidline 5 to 10 cm cranial scopic-assisted small intesSURGICAL or caudal to the telescope tinal biopsy that involves VIDEO port. If an instrument port is placement of a paramedian available, a piece of oxidized port lateral to the right rectus To see a video of a kidney regenerated cellulose can be abdominis muscle has been biopsy using a 14-gauge placed over the biopsy site reported.14 A 10-mm Babcock spring-loaded needle-core forceps is used to grasp a if hemorrhage is profuse. A biopsy needle and oxidized section of duodenum, jejusignificant benefit of laparosregenerated cellulose, visit num, or ileum and bring it copy is the ability to visualize CompendiumVet.com. to the port-site incision. The the amount of hemorrhage

QuickNotes A signiﬁcant beneﬁt of laparoscopy is the ability to visualize the amount of hemorrhage from the kidney and ensure that hemostasis has been achieved before closure.

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Large segments of small intestine can be removed through the laparoscopic-assisted incision. Using a wound retraction device minimizes pressure on the mesenteric root, preventing vascular engorgement of exteriorized bowel and facilitating its return to the peritoneal cavity after completion of the biopsy.

QuickNotes There are limitations to the use of small assist incisions for abdominal organ biopsy.

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Courtesy of Dr. Mayhew

FIGURE 4

Courtesy of Dr. Mayhew

FIGURE 3

The duodenum has been partially exteriorized through the assist incision. A biopsy sample can easily be harvested from the duodenum in addition to a pancreatic sample, if clinically indicated.

trocar–cannula assembly is removed while the device has several advantages. It prevents comBabcock forceps is still grasping the small intes- pression of the mesenteric root and subsequent tinal loop. To exteriorize the loop of intestine, vascular compromise compared with exteriorthe port incision can be enlarged to 2 to 4 cm, ization of the intestine through an unretracted as needed. A sample can then be harvested incision, thereby allowing large sections of in standard fashion. Using this technique, an intestine to be exteriorized for examination at enterostomy feeding tube can also be placed at any one time (FIGURE 3). It also allows other the time of biopsy, if clinically indicated.14 If a structures such as the pancreas and mesfeeding tube is to be placed, the section of the enteric lymph nodes to be elevated enough small intestine that is grasped must be chosen to easily collect biopsy samples (FIGURE 4). carefully because duodenostomy and jejunos- If the assist incision is directed cranially from tomy feeding tubes are usually placed in the the original subumbilical port location, it is midduodenal or proximal jejunal areas to opti- usually possible to obtain a sample from the stomach, although this may be challenging in mize nutritional absorption during feeding. I often use a modification of this technique large or deep-chested dogs. The wound retracto allow easier access to the small intestine and tion device also prevents contamination of the other organs. Once any laparoscopic procedures wound margin and has been shown in some (e.g., liver biopsy) are completed, the telescope human studies to decrease wound infection is removed from its subumbilical location and rates.15 Alternatives to the wound retractor the port incision enlarged to 3 to 4 cm to allow device include the placement of Gelpi retractors or a small Balfour retractor placement of a 2- to 4-cm in the wound to open the incilaparoscopic wound retracSURGICAL sion and decrease comprestor (Alexis Wound Retractor, VIDEO sion of the mesenteric root. Applied Medical Corp, Rancho There are limitations to the Santa Margarita, CA). Once the To see videos demonstrating use of small assist incisions retractor is in place, the circumthe placement of a wound for abdominal organ biopsy. ferential force exercised at the retractor and use of this It is difficult to exteriorize the wound margin holds open a device in exteriorizing a large proximal descending duodesmall circular orifice into the section of intestine, visit num and the ileocecocolic peritoneal cavity (FIGURE 2). CompendiumVet.com. This relatively inexpensive junction. The colon can be

Compendium: Continuing Education for Veterinarians® | April 2009 | CompendiumVet.com

Once exteriorized, the small intestine can biopsied in standard fashion. The use of a small-gauge stay suture placed at the antimesenteric border, followed by an incision with a number 11 blade, helps in the atraumatic harvesting of small intestinal biopsy samples.

Courtesy of Dr. Mayhew

FIGURE 6

Courtesy of Dr. Mayhew

FIGURE 5

The laparoscopic-assisted technique allows local lavage to be performed in a location away from the opening into the peritoneal cavity, thus minimizing peritoneal contamination.

exteriorized, although full-thickness colonic abdominal incision site, thus preventing any biopsy is strongly discouraged because of the contamination of the peritoneal cavity with high morbidity associated with dehiscence in lavage solution (FIGURE 6). After completion of this area and the excellent diagnostic quality all procedures, all abdominal wall incision sites can be closed routinely. of colonoscopic biopsy samples.4 With either the modified or unmodified technique, once the intestine is exteriorized, Pancreatic Biopsy samples can be taken using a technique simi- A laparoscopic or laparoscopic-assisted lar to that used during open celiotomy. Using a (FIGURE 4) technique can be used for pancrestay suture of 4-0 suture material, a small, full- atic biopsy. A single instrument port can be thickness bite is placed on the antimesenteric used for the laparoscopic technique if a punch side of the intestine. A number 11 blade is used technique is used, although a second port is to incise the intestine around the stay suture, necessary if use of a vessel-sealing device or ensuring that an adequate sample of mucosa as ligature is desired. A second instrument port well as submucosa and muscularis is harvested may also be necessary if significant manipula(FIGURE 5). A skin biopsy punch can also be tion of the surrounding organs is needed to used for small intestinal biopsy sample col- obtain an unobstructed view of the pancreas. lection.16 The incision(s) can be closed using A pancreatic biopsy is usually performed in 3-0 or 4-0 monofilament absorbable suture addition to biopsy of other organs; therefore, material (e.g., polydioxanone) in a simple, access is usually from instrument ports posiinterrupted or simple, continuous suture pat- tioned for these other biopsy procedures. tern. If significant narrowThe tip of the right (duoing of the luminal diameter denal) limb of the pancreas SURGICAL is anticipated after suturing, is usually the simplest to VIDEO the incisions can be closed sample. Clinical judgment in transverse fashion to prewill help the surgeon deterserve the luminal diameter mine whether this area will To see a video of pancreatic as much as possible. After provide a representative sambiopsy using a 5-mm cup closure of the biopsy site is ple. A 5-mm cup biopsy forbiopsy forceps, visit complete, local lavage can ceps can be used to carefully CompendiumVet.com. be performed away from the remove a small piece of pan-

QuickNotes The tip of the right (duodenal) limb of the pancreas is usually the simplest to sample.

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Courtesy of Dr. Stephen J. Mehler, DVM, DACVS

FIGURE 7

Clinical Pearls Using a combination of laparoscopic and laparoscopic-assisted techniques, a “one-procedure” approach to collection of high-quality organ samples can be achieved in a minimally invasive fashion. Laparoscopic-assisted techniques can allow several organs to be biopsied through one small port incision.

A laparoscopic biopsy sample is being taken from the periphery of the right pancreatic limb using a 5-mm cup biopsy instrument.

creas from the periphery of the lobe (FIGURE 7). Care should be taken to avoid performing a biopsy on the body of the pancreas (to avoid damaging pancreatic ducts) or the area where the caudal pancreaticoduodenal vessels enter the tip of the right pancreatic limb. This technique has been shown to be safe in healthy dogs, with no significant clinical abnormalities detected postoperatively, although histologically some inflammation is seen around biopsy sites.17 To reduce hemorrhage, several other techniques can be used. A pretied loop ligature can be placed around a piece of pancreas to be biopsied, or hemostatic clips can be placed in a V-shape around the tissue segment to be excised. A vessel-sealing device can also be used to harvest the sample. A recent study compared use of the Harmonic Scalpel device (Ethicon Endosurgery Inc, Cincinnati, OH) with the placement of hemostatic clips to harvest pancreatic biopsy samples laparoscopically.11 The Harmonic Scalpel led to a reduction in hemorrhage but resulted in significantly greater inflammation.

When multiple organ biopsies are required, thought should be given to the optimal position of instrument ports to allow access to all organs in question while minimizing the total number of ports required. When taking a liver biopsy sample, it is my preference to use a loop ligature around the tip of the liver lobe in all animals that are known to have coagulopathy.

Conclusion Laparoscopic and laparoscopic-assisted techniques can be used in combination to gather samples from multiple abdominal organs when diagnostic work-up of complex multiorgan pathology is performed. Even though conversion to an open approach should always be discussed with the owners, in most cases laparoscopic techniques can offer a one-procedure approach for collection of high-quality biopsy samples from multiple organs that is less invasive than open celiotomy.

References 1. Cole TL, Center SA, Flood SN, et al. Diagnostic comparison of needle and wedge biopsy specimens of the liver in dogs and cats. JAVMA 2002;220:1483-1490. 2. Rawlings CA, Diamond H, Howerth EW, et al. Diagnostic quality of percutaneous kidney biopsy specimens obtained with laparoscopy versus ultrasound guidance in dogs. JAVMA 2003;223:317-321. 3. Wang KY, Panciera DL, Al-Rukibat RK, et al. Accuracy of ultrasound-guided ﬁne-needle aspiration of the liver and cytologic ﬁndings in dogs and cats: 97 cases (1990-2000). JAVMA 2004;224:75-78. 4. Mansell J, Willard MD. Biopsy of the gastrointestinal tract. Vet Clin North Am Small Anim Pract 2003;33:1099-1116.

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5. Willard MD, Lovering SL, Cohen ND, et al. Quality of tissue specimens obtained endoscopically from the duodenum of dogs and cats. JAVMA 2001;219:474-479. 6. Evans SE, Bonczynski JJ, Broussard JD, et al. Comparison of endoscopic and full-thickness biopsy specimens for diagnosis of inﬂammatory bowel disease and alimentary tract lymphoma in cats. JAVMA 2006; 229:1447-1450. 7. Shales CJ, Warren J, Anderson DM, et al. Complications following full-thickness small intestinal biopsy in 66 dogs: a retrospective study. J Small Anim Pract 2005;46:317-321. 8. Devitt CM, Cox RE, Hailey JJ. Duration, complications, stress and pain of open ovariohysterectomy versus a simple method

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of laparoscopic-assisted ovariohysterectomy in dogs. JAVMA 2005;227:921-927. 9. Culp WTN, Mayhew PD, Bown DC. The effect of laparoscopic versus open ovariectomy on post-surgical activity in small dogs. Proc Am Coll Vet Surg Annu Symp 2008. 10. Gower S, Mayhew PD. Canine laparoscopic and laparoscopicassisted ovariohysterectomy and ovariectomy. Compend Contin Educ Pract Vet 2008;30:430-440. 11. Barnes RF, Greenﬁeld CL, Schaeffer DJ, et al. Comparison of biopsy samples obtained using standard endoscopic instruments and the harmonic scalpel during laparoscopic and laparoscopicassisted surgery in normal dogs. Vet Surg 2006;35:243-251. 12. Vasanjee SC, Bubenik LJ, Hosgood G, et al. Evaluation of hemorrhage, sample size, and collateral damage for ﬁve hepatic biopsy methods in dogs. Vet Surg 2006;35:86-91. 13. Rawlings CA, Howerth EW. Obtaining quality biopsies of the liver and kidney. JAAHA 2004;40:352-358. 14. Rawlings CA, Howerth EW, Bement S, et al. Laparoscopic-assisted enterosotomy tube placement and full-thickness biopsy of the jejunum with serosal patching in dogs. Am J Vet Res 2002;63:1313-1319. 15. Horiuchi T, Tanishima H, Tamagawa K, et al. Randomized controlled investigation of the anti-infective properties of the Alexis retractor/protector of incision sites. J Trauma 2007;62:212-215. 16. Keats MM, Weeren R, Greenlee P, et al. Investigation of Keyes skin biopsy instrument for intestinal biopsy versus a standard biopsy technique. JAAHA 2004;40:405-410. 17. Harmoinen J, Saari S, Rinkinen M, et al. Evaluation of pancreatic forceps biopsy by laparoscopy in healthy beagles. Vet Ther 2002;3:31-36.

Call for Papers Are you involved in research? Veterinary Therapeutics: Research in Applied Veterinary Medicine® is a quarterly journal dedicated to rapid publication. We invite the submission of clinical and laboratory research manuscripts in small animal, large animal, and comparative medicine, including pathophysiology, diagnosis, treatment, and prognosis. Prospective, retrospective, and corroborative studies are all welcome. Submitted articles are scheduled to be published 90 to 120 days after acceptance. Contact Cheryl Hobbs, 800-426-9119, ext 52408, or email chobbs@vetlearn.com.

It’s not just therapeutics! i !

If a dose is missed and a 30-day interval between dosing is exceeded, administer SENTINEL Flavor Tabs immediately and resume the monthly dosing schedule. Warnings: Not for use in humans. Keep this and all drugs out of the reach of children. Precautions: Do not use SENTINEL Flavor Tabs in puppies less than four weeks of age and less than two pounds of body weight. Prior to administration of SENTINEL Flavor Tabs, dogs should be tested for existing heartworm infections. Mild, transient hypersensitivity reactions manifested as labored respiration, vomiting, salivation, and lethargy have been noted in some treated dogs carrying a high number of circulating microﬁlariae.

NADA 141-084, Approved by FDA Brief Summary—For full product information see product insert. Caution: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Description: SENTINEL® (milbemycin oxime/lufenuron) Flavor Tabs® are available in four tablet sizes in color-coded packages for oral administration to dogs and puppies according to their weight. Milbemycin oxime consists of the oxime derivatives of 5-didehydromilbemycins in the ratio of approximately 80% A4 (C32H45NO7, MW 555.71) and 20% A 3 (C31H43NO7, MW 541.68). Milbemycin oxime is classified as a macrocyclic anthelmintic. Lufenuron is a benzoylphenylurea derivative with the following chemical composition: N-[2,5-dichloro-4-(1,1,2,3,3,3, -hexafluoropropoxy)-phenylaminocarbonyl]-2,6- difluorobenzamide (C17H 8CI2F 8N2O3, MW 511.15). Benzoylphenylurea compounds, including lufenuron, are classified as insect development inhibitors (IDIs). Indications and Usage: SENTINEL Flavor Tabs are indicated for use in dogs and puppies, four weeks of age and older, and two pounds body weight or greater. SENTINEL Flavor Tabs are also indicated for the prevention of heartworm disease caused by Dirofilaria immitis, for the prevention and control of flea populations, the control of adult Ancylostoma caninum (hookworm), and the removal and control of adult Toxocara canis and Toxascaris leonina (roundworm) and Trichuris vulpis (whipworm) infection. Lufenuron controls flea populations by preventing the development of flea eggs and does not kill adult fleas. Concurrent use of an adulticide product may be necessary for adequate control of adult fleas. Dosage and Administration: SENTINEL Flavor Tabs are given orally, once a month, at the recommended minimum dosage of 0.23 mg/lb (0.5 mg/kg) milbemycin oxime and 4.55 mg/lb (10mg/kg) lufenuron. Dogs over 100 lbs. are provided the appropriate combination of tablets.

Adverse Reactions: The following adverse reactions have been reported in dogs after giving milbemycin oxime or lufenuron: vomiting, depression/lethargy, pruritus, urticaria, diarrhea, anorexia, skin congestion, ataxia, convulsions, hypersalivation, and weakness. Efficacy: Milbemycin Oxime Milbemycin oxime provided complete protection against heartworm infection in both controlled laboratory and clinical trials. In laboratory studies, a single dose of milbemycin oxime at 0.5 mg/kg was effective in removing roundworm, hookworm, and whipworm. In well-controlled clinical trials, milbemycin oxime was also effective in removing roundworms and whipworms and in controlling hookworms. Efficacy: Lufenuron Lufenuron provided a 99% control of flea egg development for 32 days following a single dose of lufenuron at 10 mg/kg in studies using experimental flea infestations. In well-controlled clinical trials, when treatment with lufenuron tablets was initiated prior to the flea season, mean flea counts were lower in lufenuron-treated dogs versus placebo-treated dogs. After 6 monthly treatments, the mean number of fleas on lufenuron-treated dogs was approximately 4 compared to 230 on placebo-treated dogs. When treatment was initiated during the flea season, lufenuron tablets were effective in controlling flea infestations on dogs that completed the study. The mean flea count per lufenuron-treated dog was approximately 74 prior to treatment but had decreased to 4 after six monthly doses of lufenuron. A topical adulticide was used in the first eight weeks of the study to kill the pre-existing adult fleas.

SENTINEL Flavor Tabs are palatable and most dogs will consume the tablet when offered by the owner. As an alternative to direct dosing, the tablets can be hidden in food. Administer SENTINEL Flavor Tabs to dogs, immediately after or in conjunction with a normal meal. Food is essential for adequate absorption of lufenuron.

For technical assistance or to report suspected adverse events, call 1-800-332-2761.

SENTINEL Flavor Tabs must be administered monthly, preferably on the same date each month. In geographic areas where mosquitoes and ﬂeas are seasonal, the treatment schedule should begin one month prior to the expected onset and should continue until the end of “mosquito and ﬂea season.” In areas with year-round infestations, treatment should continue through the entire year without interruption.

Manufactured for: Novartis Animal Health US, Inc. Greensboro, NC 27408, USA

NAH/SEN-FCT/BS/6

06/08

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In collaboration with the American College of Veterinary Surgeons

Laparoscopic and Laparoscopic-Assisted Cryptorchidectomy in Dogs and Cats ❯❯ Philipp Mayhew, BVM&S, MRCVS, DACVS Columbia River Veterinary Specialists Vancouver, Washington

Abstract: There are many applications for laparoscopy in small animal surgery. A relatively simple one is abdominal cryptorchid castration. Laparoscopic examination of the peritoneal cavity can both aid in the diagnosis of abdominal cryptorchidism and allow treatment using either a totally laparoscopic or a laparoscopic-assisted technique. Minimally invasive cryptorchid castration obviates the need for “open” celiotomy and may thereby reduce postoperative discomfort and wound-related complications in these patients.

At a Glance Advantages Page 275

Disadvantages Page 275

Preoperative Assessment Page 275

Instrumentation Page 276

Surgical Techniques Page 278

TO LEARN MORE

For a description of conventional surgical approaches to cryptorchid testes, see the June 2008 article “Cryptorchidism,” available at

CompendiumVet.com.

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uring embryonic development in male dogs and cats, contraction of the gubernaculum causes progressive migration of the testes from a location just caudal to the kidney to their normal position in the scrotum.1 This migration is typically complete by 2 months of age but can take place as late as 6 months of age in some breeds.1 The cause of cryptorchidism has not been completely elucidated but is likely multifactorial.1 Migration of the testis can cease at any time, with the result that one or both testes can remain in the peritoneal cavity, within the inguinal rings, or in the inguinal area cranial to the scrotum. Owners should be advised that there are several important reasons to castrate a cryptorchid pet. First, cryptorchidism is thought to be a sex-linked autosomal recessive trait in dogs. Further breeding could lead to propagation of this undesirable trait. Second, cryptorchid testes are prone to several pathologic states. CE Article #1

Cryptorchidism Stephen J. Birchard, DVM, MS, DACVS Michael Nappier, DVM The Ohio State University

ABSTRACT: Cryptorchidism is a common clinical problem in dogs and cats. Retained testes can

be unilateral or bilateral, are usually small and atrophied, and vary in location.These factors make

diagnosis and surgical removal challenging in some animals. Diagnosis is confirmed using a variety of

modalities, including diagnostic imaging in difficult cases. Surgical removal of the affected and normal

testes is the treatment of choice.The surgical approach and technique used depend on the location of the retained testis.

ryptorchidism is one of the most common congenital defects seen in small animal practice. In dogs, the reported prevalence of cryptorchidism ranges from 0.8% to 10%.1 The defect is a sex-linked autosomal recessive trait that is common in certain breeds,2 such as Chihuahuas, miniature schnauzers, Pomeranians, poodles, Shetland sheepdogs, and Yorkshire terriers. Smaller breeds are 2.7 times more likely to be cryptorchid than larger breeds.3 In cats, one study found Persians to be predisposed to cryptorchidism.4 Due to the thermal suppression of sperm production, bilaterally cryptorchid animals are sterile, while unilaterally cryptorchid animals are usually fertile.5 Undescended testes are 13.6 times more likely to develop neoplasia (Figure 1) than normal testes and are at increased risk of torsion.6,7 Undescended testes vary in their anatomic position. They may be located in the prescrotal area, inguinal region, or abdominal cavity. In a study of 240 cryptorchid dogs and 50 cryptorchid cats, retained testes were most commonly found in the right inguinal region in • Take CE tests dogs and in the left or right • See full-text articles inguinal region in cats.8 LocatCompendiumVet.com ing an ectopic testis can be dif-

June 2008

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ficult in some animals. A thorough and systematic approach to patient evaluation is necessary to efficiently find and remove the abnormal testis. Although surgery for removal of cryptorchid testes is well described in the veterinary literature, approaches to diagnosis and localization of ectopic testes have not been extensively described. This lack, coupled with the increasing number of animals that present with an unknown neutering history (e.g., rescue animals), emphasizes the need for a discussion of a thorough clinical approach to cryptorchidism. This article describes a systematic approach to the diagnosis and surgical treatment of cryptorchidism in dogs and cats, including the integration of the history; physical examination; blood tests, including hormone assays; and diagnostic imaging to make a definitive anatomic diagnosis. Various options for surgical removal of the retained testis are also described.

DIAGNOSIS History Most authors agree that if one or both testes are not present in the scrotum by 2 months of age, the animal is cryptorchid. 2 It is highly unlikely that the testes will descend into the scrotum after this age. The clinical signs of COMPENDIUM

Testicular tumors develop much more frequently in cryptorchid testes than in scrotal testes. In one study, the risk of tumor development in cryptorchid testes was 13.6 times the risk in scrotal testes.2 Inguinally retained testes appear to be at even higher risk of developing neoplasia than abdominally retained testes.3 The risk of testicular torsion is also increased for cryptorchid testes, with torsed testes often being neoplastic.4 If, on physical examination, one or both testes are not present inguinally or scrotally, the missing testis is most likely within the peritoneal cavity. Palpation should be performed carefully because cryptorchid testes are often smaller than descended testes and can be difﬁcult to ﬁnd. Traditionally, abdominal testes have been removed through either a ventral midline celiotomy or a parapreputial laparotomy.5 Totally laparoscopic or laparoscopic-assisted techniques now exist, allowing removal of intraabdominal testes through much smaller incisions. Neoplastic cryptorchid testes can also be removed laparoscopically, although if the tumor is very large, open surgery may remain more practical.

Compendium: Continuing Education for Veterinarians® | June 2009 | CompendiumVet.com

Advantages A minimally invasive approach to abdomi-nal cryptorchid testis removal reduces tissue trauma and is likely to reduce postoperative pain and wound healing complications com-pared with open laparotomy. If localization of a cryptorchid testis is challenging, laparo-scopic examination of the caudal peritoneal cavity and the entrance to the inguinal rings provides excellent visualization and can help to rule out the diagnosis of abdominal cryptorchid-ism. This may help to minimize iatrogenic dam-age to surrounding structures, which has been attributed in some cases to inadequate visual-ization when small paramedian laparotomies are performed. Such damage includes inad-vertent prostatectomy and ureteral or urethral trauma.6–8

Disadvantages The principal disadvantage of laparoscopy is the need for specialized equipment and the associ-y ated costs. Adequate training is also necessary to perform laparoscopic procedures and to use the equipment appropriately. Although surgi-cal time can initially be longer than that for an open procedure, with experience, laparoscopic cryptorchidectomy is likely to become as efﬁcient, if not faster than, its open counterpart.

Preoperative Assessment A careful history should be taken for any male cat or dog in which two testes cannot be palpated in the inguinal area to ensure that one or both testes have not been removed previously. Generally, a male dog or cat in which one or both testes are absent from the scrotum at 6 months of age is classified as cryptorchid because scrotal migration of a testis after this time is extremely unlikely.1 It is important to assess the inguinal area carefully with the animal under heavy sedation or general anesthesia so as not to miss the presence of an inguinal testis. If one testis is present scrotally and one abdominally, it is also helpful to identify whether the right or left testis is present

It is with great pleasure that I announce the new partnership of the American College of Veterinary Surgeons (ACVS) with Compendium in the “Surgical Views” series. The expertise and experience of the ACVS Diplomates will add greatly to the value of the series. Elizabeth M. Hardie, DVM, PhD, DACVS North Carolina State University

The ACVS is proud to enter into this new cooperative venture with Compendium and series editor Elizabeth Hardie. The ACVS is well known as a world leader in developing innovative surgical procedures and disease research, yet continuing education is also one of the pillars of the College. In addition to presenting at our yearly symposium, ACVS Diplomates host and produce much of the continuing education in veterinary surgery in the United States. Now, with this collaboration, we are expanding our education outreach to a new venue. The ACVS hopes you will enjoy and proﬁt from our Diplomates’ contributions to this distinct continuing education effort. Larry R. Bramlage, DVM, MS, DACVS Chair, ACVS Board of Regents

To locate a Diplomate, ACVS has an online directory that includes practice setting, species emphasis, and research interests (acvs.org/VeterinaryProfessionals/FindaSurgeon).

QuickNotes Generally, a male dog or cat in which one or both testes are absent from the scrotum at 6 months of age is classiﬁed as cryptorchid because scrotal migration of a testis after this time is extremely unlikely.

within the peritoneal cavity. This can be done by gentle manipulation of the scrotal testis in a cranial direction, which will usually reveal the side on which it is located. If no inguinal testes are palpated, it can be assumed that the missing testes are in either the inguinal canal (which is uncommon) or the abdomen. Abdominal ultrasound can be used to conﬁrm the presence SURGICAL of abdominal or inguinal canal testes VIDEO in most cases. If doubt still remains about the presence or absence of testes, a human chorionic gonadotropin To see a video of manipulation to stimulation test can be performed to identify which testis is cryptorchid, conﬁrm the presence of testicular tisvisit CompendiumVet.com. sue.5 For this test, serum samples are

CompendiumVet.com | June 2009 | Compendium: Continuing Education for Veterinarians®

275

FIGURE 1

FIGURE 2

In many cases, the cryptorchid testis is readily visible during initial visualization of the peritoneal cavity. In this case, the testis can be seen on the right side, lateral to the descending colon and bladder.

Port position for a totally laparoscopic approach for abdominal cryptorchidectomy in a dog. The subumbilical telescope port is placed first, followed by two paramedian instrument ports.

QuickNotes Laparoscopic examination of the caudal abdomen is a minimally invasive modality for conﬁrming the presence or absence of abdominal testes.

276

Laparoscopic examination of the caudal abdomen is a minimally invasive modality for conﬁrming the presence or absence of abdominal testes, and laparoscopic or laparoscopicassisted techniques have been described for removal of abdominally cryptorchid testes.

collected before and 2 hours after administra- Instrumentation tion of human chorionic gonadotropin (50 IU/ As well as the basic components of an endokg IM) and submitted for testosterone assay. scopic tower,10 other equipment required to Unilateral or bilateral monorchidism is very perform laparoscopic and laparoscopic-assisted rare; therefore, it is most likely that abdomi- cryptorchidectomy includes a laparoscope, two nal testes are present,7,9 making exploration of or three trocar–cannula assemblies, and lapthe peritoneal cavity a reasonable next step. aroscopic surgical instruments. The most comTypically, exploration is accomplished via open monly used laparoscope size is 5 or 10 mm, and surgery through a ventral midline celiotomy or the most common lens angles are 0° and 30°. a paramedian laparotomy.5 In cats, a standard Trocar–cannula assemblies can be disposable or ventral midline laparotomy that must usually reusable and are usually 6 mm in diameter to extend caudally to the pubis is performed. ﬁt 5-mm instrumentation. Typically, sterilizable, reusable cannulas are more cost-effective than single-use devices for veterinary use. TO LEARN MORE Instruments essential for laparoscopic cryptorchidectomy include a blunt probe for tissue manipulation and Kelly or Babcock forceps for grasping the testis, spermatic cord, and Basic laparoscopic equipment and the Hasson gubernaculum. For hemostasis during totally and Veress needle techniques are described in the August 2008 article, “Canine Laparoscopic laparoscopic cryptorchidectomy, either a vesand Laparoscopic-Assisted sel-sealing device (e.g., Ligasure [Valleylab Inc., Ovariohysterectomy and Boulder, CO], Enseal [Ethicon Endosurgery, Ovariectomy,” available at Cincinnati, OH], Harmonic Scalpel [Ethicon CompendiumVet.com. Endosurgery, Cincinnati, OH]) can be used. A video demonstrating If these devices are not available, hemostasis the Hasson technique can be achieved using either hemostatic clips is also available at dispensed by a laparoscopic clip applier or CompendiumVet.com. extracorporeal suturing. A knot pusher is used

Compendium: Continuing Education for Veterinarians® | June 2009 | CompendiumVet.com

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©2008 Fort Dodge Animal Health, a division of Wyeth. 1. Michael P. Ward, et al. Prevalence of and risk factors for leptospirosis among dogs in the United States and Canada: 677 cases (1970-1998). JAVMA, Vol. 220, No. 1, January 1, 2002. 2. George E. Moore, et al. Canine Leptospirosis, United States, 2002-2004. Emerging Infectious Diseases, www.cdc.gov/ncidod/eid/vol12no03/05-0809.htm. Vol. 12, No. 3, March 2006. 3. Michael P. Ward, et al. Evaluation of environmental risk factors for leptospirosis in dogs: 36 cases (1997-2002). JAVMA, Vol. 225, No. 1, July 1, 2004.

FIGURE 3

The spermatic cord and vascular pedicle of the testis can be seen entering the inguinal ring in this dog. This finding confirms that the testis is located extraperitoneally.

to place extracorporeal sutures. If a testicular tumor is suspected, resection and placement into a specimen retrieval bag before removal from the peritoneal cavity is advised to avoid port site metastasis.

QuickNotes The possibility of conversion to an open approach should always be anticipated with any laparoscopic procedure.

SURGICAL VIDEO

Surgical Techniques Patient Preparation and Positioning Dogs and cats with cryptorchid testes should be positioned in dorsal recumbency on the surgical table. The inguinal area should be thoroughly palpated again to rule out an inguinally located testis and prevent unnecessary laparotomy or laparoscopy. The entire ventral abdomen from the scrotum to the xiphoid process and laterally to the midabdominal level should be aseptically prepared, as the possibility of conversion to an open approach should always be anticipated with any laparoscopic procedure. After initiating the pneumoperitoneum, place the animal in a 20° to 30° “head down” (Trendelenburg) position to allow caudal peritoneal organs to move cranially, thus improving visualization of the area. In some cases, it may also be beneﬁcial to tilt the animal laterally to better visualize one or both testes.

To see a video of the use of a vessel-sealing device to seal and section the gubernaculum, spermatic cord, and vascular pedicle, visit CompendiumVet.com.

278

FIGURE 4

Only the gubernaculum (no vascular pedicle or spermatic cord) can be seen entering the inguinal ring in this dog. This confirms that the testis is within the abdomen, and a thorough examination of the caudal peritoneal cavity should reveal its location.

Once the telescope port has been established, an instrument port can be established using a 5or 10-mm trocar–cannula assembly under direct visualization in a paramedian location (lateral to the prepuce in dogs; in the left or right caudal quadrant of the abdomen in cats) on the right or left side, depending on which testis is located in the abdomen. Every effort should be made to avoid iatrogenic damage to the caudal superﬁcial epigastric vessels during cannula placement. In most bilaterally cryptorchid animals, the side that the instrument port is placed on is not critical because both testes will still be retrievable from the same port.9 A totally laparoscopic technique is usually performed using a three-port technique. A two-port technique can be used if an operating laparoscope with a working channel is used. A camera port should be placed in a subumbilical position. Two more instrument ports are established in paramedian (lateral to the prepuce) positions on both sides of the prepuce in dogs (FIGURE 1) and in a triangulating position around the caudal abdomen in cats.

Exploration of the Caudal Peritoneal Cavity Port Position Laparoscopic-assisted cryptorchidectomy can be performed using a two-port technique. A telescope port is established in a subumbilical location, using either the Hasson technique or a Veress needle technique. These techniques were described in an earlier Surgical Views article.10

In many cases, after establishment of a pneumoperitoneum, the abdominal testis can be seen immediately on entering the peritoneal cavity with the laparoscope (FIGURE 2). However, if confusion exists, the area of the internal inguinal ring should be visualized. If the spermatic cord and vascular pedicle of the testis are seen entering the ring, the testis is in an extraperito-

Compendium: Continuing Education for Veterinarians® | June 2009 | CompendiumVet.com

neal location, either within the inguinal canal or (more likely) in an inguinal location (FIGURE 3). The surgeon should reevaluate the inguinal area if no testis was palpated in that location previously. If only the gubernaculum is seen entering the inguinal ring, the testis is located within the peritoneal cavity, and further inspection of the caudal abdomen usually locates it. Gentle traction can also be placed on the gubernaculum to help in localization (FIGURE 4). In some cases, the testis is obscured by the bladder or other surrounding structures.

Laparoscopic-Assisted Cryptorchidectomy The laparoscopic-assisted cryptorchidectomy technique provides a rapid, simple way to recover an abdominal testis and ligate the vascular pedicle and spermatic cord outside the abdominal cavity, thereby obviating the need for intracorporeal ligation techniques.9 In this technique, laparoscopic Kelly or Babcock forceps are placed through the instrument port to grasp the testis or the spermatic cord. At this point, it is helpful to evacuate the pneumoperitoneum to decrease tension during elevation of the testis. Enlarge the port incision by separating the parallel ﬁbers of the rectus abdominus just enough to remove the

Clinical Pearls Laparoscopic examination of the caudal peritoneal cavity can be very helpful in localizing cryptorchid testes and can prevent an unnecessary celiotomy. Laparoscopic-assisted abdominal cryptorchidectomy is a simple, rapid technique that does not require specialized equipment beyond the basic laparoscopic instrumentation. In many cases, neoplastic cryptorchid testes can be removed using a laparoscopic technique. If the testis is ≥8 cm in diameter or has signiﬁcant adhesions to surrounding structures, it may be more practical to perform a ventral midline celiotomy.

testis from the peritoneal cavity. Once the testis has been exteriorized, clamp and double ligate the spermatic cord and vascular pedicle before sectioning. It is important to ensure that ligated pedicles are not bleeding and do not become caught in the subcutaneous fat or muscular tissue of the body wall as they are returned to the peritoneal cavity. If both testes are in the peritoneal cavity, they can usually be recovered through the same port incision. To locate the second testis, reestablish the pneumoperitoneum. If the instrument port was enlarged to recover the first testis, use a larger cannula, hold a moistened sponge around the cannula, or place a temporary purse-string suture around the cannula to prevent leakage of carbon dioxide during reinsertion of the cannula. The second testis can then be withdrawn and ligated in the same manner as the first. If the second testis cannot be advanced to the port site, establish a third port on the opposite side of the prepuce (FIGURE 1) and follow the above steps to withdraw the second testis, although in my experience, this is unlikely to be necessary. The port site incision(s) should then be closed, making sure that the ventral sheath of the rectus abdominus is adequately sutured to prevent herniation of abdominal contents, which can occur through defects as small as 5 mm. After closure of the instrument port incisions and before closure of the telescope port, it is advisable to briefly reestablish the pneumoperitoneum and reinsert the telescope to ensure that good hemostasis has been maintained. Finally, remove the telescope, thoroughly purge the pneumoperitoneum from the peritoneal cavity, and close the telescope portal routinely.

QuickNotes If both testes are in the peritoneal cavity, they can usually be recovered through the same port incision.

Totally Laparoscopic Cryptorchidectomy In the totally laparoscopic cryptorchidectomy technique, the vascular supply and spermatic cord are ligated within the peritoneal cavity before the testis is removed from the abdomen. If the testis is directly visible, it can be grasped with laparoscopic Kelly or Babcock forceps and elevated (FIGURE 5), allowing the vascular pedicle and spermatic cord to be moved away from surrounding structures in readiness for ligation. A vessel-sealing device can be placed into the second instrument port, and the guberCompendiumVet.com | June 2009 | Compendium: Continuing Education for Veterinarians®

279

FIGURE 5

The testis is elevated for totally laparoscopic cryptorchidectomy to allow better access to the vascular pedicle and spermatic cord during intracorporeal ligation of these structures.

naculum, spermatic cord, and vascular pedicle sealed and subsequently sectioned. The vascular pedicle can be substantial in large dogs, and care should be taken to ensure adequate hemostasis. The Ligasure and Enseal devices are both indicated to seal vessels up to 7 mm in diameter, and I have used them to seal the pampiniform plexus effectively. However, it QuickNotes is suggested that the vascular pedicle be double The vascular pedicle sealed—once proximally and once distally— before sectioning (FIGURE 6). If a vessel-sealcan be substantial ing device is not available, hemostasis can be in large dogs, and achieved using hemostatic clips delivered via a care should be laparoscopic clip applier. Although 5-mm laptaken to ensure ade- aroscopic clip appliers are available, medium quate hemostasis. or large clips are generally delivered in a 10-mm clip applier. To reduce costs associated with the use of expensive single-use disposable clip appliers, multiﬁre sterilizable clip appliers that can be loaded with cartridges of clips are available (M/L-10, Microline Pentax, Beverly, MA). Another alternative for achieving hemostasis of the pedicle is the placement of extracorporeal ligatures. To place extracorporeal sutures, pass a piece of suture material through one cannula and around the pedicles. Withdraw the suture through the same SURGICAL cannula, tie a modiﬁed Roeder knot VIDEO outside the peritoneal cavity, push the knot into place through the cannula, To see a video of testis and tighten it around the pedicle using removal through the a laparoscopic knot pusher.11 Although subumbilical port, visit this is the least expensive technique CompendiumVet.com. (it does not require any expensive

280

FIGURE 6

The vascular pedicle after sectioning using the vessel-sealing device. The pedicle has been sealed in two different locations approximately 1 cm apart to ensure good hemostasis.

disposable equipment), it is likely to be the most time-consuming because these sutures are tedious to place; however, a rapid learning curve has been seen in studies that used extracorporeal suturing.12 When laparoscopic cryptorchidectomy is performed, the testis must be withdrawn through one of the ports. One of the parapreputial ports can be used for this purpose, or the telescope can be replaced into one of the instrument ports and the testis withdrawn through the subumbilical port. If the subumbilical port is used, any enlargement of the port incision will be through the linea alba, resulting in less muscular trauma and therefore possibly less postoperative pain than if a paramedian instrument port is enlarged. After laparoscopic cryptorchidectomy, it is not necessary to reestablish the pneumoperitoneum because the pedicles are inspected for hemostasis immediately after they have been sealed or ligated and sectioned. After the testis has been removed, all remaining ports can be closed routinely.

Resection of Neoplastic or Torsed Cryptorchid Testes Cryptorchid testes are predisposed to neoplasia and torsion, both of which are indications for surgical excision.1–4 Whether a laparoscopic approach is feasible in these situations depends on several variables. If the testis is very large (8 to 10 cm), a laparoscopic approach may be less practical because a large incision will be required to retrieve the testis after its pedicles have been ligated. A second potential problem

Compendium: Continuing Education for Veterinarians® | June 2009 | CompendiumVet.com

is the presence of adhesions to other structures, speciﬁcally the bladder, ureters, prostate, and lower gastrointestinal tract. If the surgeon has any concern about the involvement of these structures or encounters technical difﬁculties while dissecting adhesions, conversion to an open approach should be considered. However, laparoscopic resection of a neoplastic testis has been reported in the veterinary

literature.13 In my experience, most neoplastic abdominally cryptorchid testes remain small and mobile enough to be resected laparoscopically in a manner similar to those described above for removal of nonneoplastic testes. If a testis is suspected to be neoplastic, it should be placed in a specimen retrieval bag before being pulled through the instrument port to reduce the possibility of port-site metastasis.

References 1. Romagnoli SE. Canine cryptorchidism. Vet Clin North Am Small Anim Pract 1991;21:533-544. 2. Hayes HM, Pendergrass TW. Canine testicular tumors: epidemiological features of 410 dogs. Int J Cancer 1976;18:482-487. 3. Reif JS, Maguire TG, Kenney RM, et al. A cohort study of canine testicular neoplasia. JAVMA 1979;175:719-723. 4. Pearson H, Kelly DF. Testicular torsion in the dog: a review of 13 cases. Vet Rec 1975;97:200-204. 5. Birchard SJ, Nappier M. Cryptorchidism. Compend Contin Educ Pract Vet 2008;30:325-336. 6. Bellah JR, Spencer CP, Salmeri KR. Hemiprostatic urethral avulsion during cryptorchid orchiectomy in a dog. JAAHA 1989;25:553556. 7. Millis DL, Hauptman JG, Johnson CA. Cryptorchidism and monorchidism in cats: 25 cases (1980-1989). JAVMA 1992;200: 1128-1130. 8. Schultz KS, Waldron DR, Smith MM. Inadvertant prostatecto-

my as a complication of cryptorchidectomy in four dogs. JAAHA 1996;32:211-214. 9. Miller NA, Van Lue SJ, Rawlings CA. Use of laparoscopic-assisted cryptorchidectomy in dogs and cats. JAVMA 2004;224:875878. 10. Gower S, Mayhew PD. Canine laparoscopic and laparoscopicassisted ovariohysterectomy and ovariectomy. Compend Contin Educ Pract Vet 2008;30:430-440. 11. Stoloff DR. Laparoscopic suturing and knot tying techniques. In: Freeman LJ, ed. Veterinary Endosurgery. St. Louis: Mosby; 1999:85. 12. Mayhew PD, Brown DC. Comparison of three techniques for ovarian pedicle hemostasis during laparoscopic-assisted ovariohysterectomy. Vet Surg 2007;36:541-547. 13. Pena FJ, Anel L, Dominguez JC, et al. Laparoscopic surgery in a clinical case of seminoma in a cryptorchid dog. Vet Rec 1998;142:671-672.

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In collaboration with the American College of Veterinary Surgeons

Endoscopic Removal of Urinary Calculi ❯❯ Clarence A. Rawlings, DVM, PhD, DACVSa The University of Georgia

At a Glance Patient and Technique Selection Page 476

Preoperative Patient Management Page 477

Transurethral Cystoscopy Page 478

Laparoscopic-Assisted Cystoscopy Page 479

Intraoperative Nephroscopy and Cystoscopy Page 482

Other Minimally Invasive Techniques Page 484

Postoperative Patient Management Page 484

aDr. Rawlings discloses that he

has received ﬁnancial support from Biovision, Covidien, Ellman International, Endoscopic Support Services, and Karl Storz Veterinary Endoscopy.

476

espite advances in the prevention 7-kg female dog can usually accommodate and management of urinary cal- a 2.7-mm cystoscope with a 14.5-Fr sheath. culi, calculus removal remains a These dimensions should allow a calcucommon need in small animal practice. In lus 6 to 7 mm in diameter to be removed fact, changes in calculus management have through the urethra. In male dogs, tranincreased the percentage of calculi that are surethral removal is limited to much smaller difﬁcult to manage medically.1 Endoscopic calculi because the stones must traverse the techniques that reduce the need for calcu- os penis region of the urethra. Calculi in lus removal by traditional laparotomy and male cats can be removed by laparoscopiccystotomy have been developed. In my assisted cystoscopy, but the urethra is too experience, most cystic and urethral cal- small for current transurethral cystoscopy culi can be removed by transurethral or techniques. The ability to endoscopically laparoscopic-assisted cystoscopy. These remove cystic and urethral calculi has techniques decrease trauma to and urine largely replaced the need for hydropulsion contamination of the abdomen. Endoscopy in female dogs. also improves the ability to examine the Transurethral cystoscopic calculus removal urinary system for disease and the pres- in female dogs has been enhanced in some ence of more calculi. specialty hospitals by cystoscopic lithotripsy.3–11 As with basket removal of calculi Patient and Technique Selection from the lower urinary tract, lithotripsy can Nearly all calculi in female dogs and cats be more widely used in female dogs than can be removed by either transurethral male dogs. Cystic lithotripsy is indicated cystoscopy or laparoscopic-assisted cystos- for calculi that are too large to be removed copy, in my experience. Most male dogs cystoscopically with baskets. The current can be treated with laparoscopic-assisted contraindications to lithotripsy are large cystoscopy.2 Transurethral cystoscopy is calculi and high numbers of calculi in relapreferred for female cats and dogs because tion to the operator’s expertise. Trauma and it is less invasive than laparoscopic-assisted time required to fragment and remove large techniques; however, calculi must be small or multiple calculi can be excessive during enough to be pulled through the urethra if inappropriate lithotripsy. transurethral cystoscopy is to be successful. Laparoscopic-assisted cystoscopy through Size criteria are continually being modi- one or two small abdominal incisions has ﬁed, but I have found that in female cats proven to be an effective and relatively simple and dogs, calculi can be removed that are way to remove calculi from female and male twice the diameter of the largest cystoscope dogs and cats.2–12 The primary contraindicaappropriate for the patient. For example, a tion is the presence of stones several centi-

Compendium: Continuing Education for Veterinarians® | October 2009 | CompendiumVet.com

meters in diameter that require removal through y a long abdominal incision. Although cystoscopy can still be used to examine the urinary sys-tem after removal of larger calculi, the longer incision might as well be for a traditional lapa-y rotomy and cystotomy. The presence of a very large number of smaller calculi can discourage some endoscopists, but the use of lavage and suction permits removal of larger numbers off stones during laparoscopic-assisted cystoscopy. In the hospitals in which I practice, tradi-tional laparotomy and cystotomy are usuallyy reserved for patients with very large calculi or those requiring other complex abdominal pro-cedures, such as nephrectomy. However, some additional procedures are better performed during laparoscopy than by laparotomy. An example would be a liver biopsy, for which lap-aroscopy is minimally invasive and can be used to obtain multiple tissue samples from selected sites as well as a bile sample for culture. Some subspecialists successfully remove calculi from the ureters and bladder using advanced endourologic techniques.2–11 These techniques are widely performed in people; in the veterinary setting, they have been most commonly applied in larger female dogs. Lithotripsy and endoscopic removal of calculi from the kidneys and ureters are typically referral procedures, in contrast to the endoscopic techniques for transurethral and laparoscopic-assisted cystoscopic procedures, which have been performed by general practitioners trained in endoscopy.

Surgical Views is a collaborative series between the American College of Veterinary Surgeons (ACVS) and Compendium. Upcoming topics in this series include vacuumassisted wound closure, conventional foreign object removal, and suspensory ligament rupture. All Surgical Views articles are peer-reviewed by ACVS diplomates. To locate a diplomate, ACVS has an online directory that includes practice setting, species emphasis, and research interests (acvs.org/VeterinaryProfessionals/FindaSurgeon).

ing techniques are commonly used, but urinary contrast procedures seem to be less frequently employed. Ultrasonography by an experienced ultrasonographer is particularly useful for monitoring dogs with recurrent calculi, especially when the calculi are small. If present, prerenal and postrenal azotemia or uremia should be addressed before calculus removal in all but the most urgent cases of obstruction. Conﬁrmed renal dysfunction may require modiﬁcation of the plan for calculus removal. In patients with a preexisting urinary FIGURE 1

Courtesy of Chris Herron

Preoperative Patient Management Patient evaluation is directed toward determining renal function, the presence of urinary tract infection, systemic organ function, and the number, size, and distribution of calculi. Tests include a complete blood count, serum chemistry proﬁle, urinalysis, and urine culture. Abdominal radiography is indicated to determine the size, number, and distribution of radiopaque calculi. Radiopaque calculi are composed of struvite, silica, and calcium oxalate; more radiolucent calculi contain urate, uric acid, and cystine. Abdominal ultrasonography is preferred to radiography for detecting radiolucent calculi and helps obtain more information about renal structure and function. Both imag-

Calculus removal from the urethra, bladder, proximal ureter, and renal pelvis frequently involves a 2.7- or 1.9-mm cystoscope with a basket retrieval instrument. The basket retrieval instrument is passed through the cystoscope’s operating channel, and the basket is kept inside the channel until a stone is visualized through the scope. To capture the stone, the basket is advanced through the end of the channel. Once around the calculus, the basket is tightened.

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FIGURE 2

Radiograph showing a urethral calculus (circle). Urine culture results at the time of radiography had no bacterial growth. Using radiography and ultrasonography, the dimensions of the calculi were measured to determine whether transurethral cystoscopy could be used to remove them. The dog weighed 10 kg, and the largest calculus appeared to be 5 mm in diameter.

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tract infection, culture and antibiotic administration should be attempted before emergency relief of urinary obstruction. In patients with recurrent urinary tract infections, collection of a bladder mucosal sample for culture should be considered during calculus removal. Regardless of the protocol used to control urine contamination of the abdomen, the risk of contamination dictates the use of antibiotics during cystoscopy and laparoscopicassisted cystoscopy.

For descriptions of other laparoscopic techniques, see “Laparoscopic-Assisted and Laparoscopic Prophylactic Gastropexy: Indications and Techniques” (February 2009) and “Techniques for Laparoscopic and Laparoscopic-Assisted Biopsy of Abdominal Organs” (April 2009), available on CompendiumVet.com.

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Endoscopic view of the larger calculus at the outflow tract, just before being snared with the basket retrieval device.

Transurethral Cystoscopy Calculus removal using a stone basket is less invasive than and preferred to cystotomy during laparotomy or laparoscopic-assisted cystoscopy if the calculi are small enough for removal via the urethra. The clinician must be a competent and experienced cystoscopist to attempt calculus removal using a basket retrieval instrument. In general, basket removal can be attempted for calculi <3 mm in diameter in female cats and male dogs. In female dogs, calculi removed

The removed calculi were 6 mm in diameter. Despite attempts to medically prevent recurrence, clinical signs developed, and more calculi were diagnosed using ultrasonography and removed by cystoscopy.

Courtesy of Clarence A. Rawlings, DVM, PhD, DACVS

Transurethral cystoscopy in a 6-year-old spayed schnauzer. The patient had a 3-week history of repeated straining to void and inappropriate voiding inside the house. The dog had previously had a cystotomy to remove calcium oxalate calculi.

using this method should be no more than twice the diameter of the largest cystoscope that can be placed in the urethra. Commonly used cystoscope sizes are 1.9 mm for female cats and dogs weighing <5 kg, 2.7 mm for female dogs between 5 and 15 kg, and 3.5 or 4.0 mm for larger female dogs (FIGURE 1). The two smaller cystoscope sizes can be used to retrieve calculi in nearly all female dogs. A 1.9-mm cystoscope and a basket retrieval instrument have been used to remove calculi during cystoscopic examination of the urethra and bladder of male cats after perineal urethrostomy. It is not uncommon during transurethral cystoscopic calculus removal to find lesions that may be related to recurrent urinary tract infections. These include strictures, transitional cell carcinoma, inflammatory polyps, and persisting cystotomy closure sutures. Basket retrieval devices with three or four wires are preferred (FIGURE 1). They should easily fit through the operating channel of the cystoscope. After diagnostic cystoscopy is used to examine the lower urinary tract and flush the bladder, the basket is passed through the

Compendium: Continuing Education for Veterinarians® | October 2009 | CompendiumVet.com

Laparoscopic-Assisted Cystoscopy Cystoscopy via minilaparotomy was initially reported as laparoscopic-assisted cystoscopy.2 Laparoscopic assistance requires a laparoscope and two trocars, in contrast to the more recently reported technique of percutaneous cystolithotomy, also called keyhole transvesicular cystourethroscopy.12 Both laparoscopic-assisted and

FIGURE 3

Courtesy of Chris Herron

operating channel (FIGURE 2). Individual techniques vary, but I prefer to have the bladder only mildly distended and to keep the lavage flow rate low. This practice concentrates the calculi and reduces the swirling effect that can be produced by higher flow rates. Having the patient in dorsal recumbency and tilted with the head up can also move the calculi toward the outflow tract. External abdominal manipulation of the bladder can be helpful. The basket is opened in the area of the calculi and gradually closed during cystoscopic examination. Some clinicians prefer to tighten the wires very securely around the stones. I often use less force to cradle the calculi during extraction. The basket distention helps to gradually dilate the urethra during extraction and reduces the likelihood of calculus fragmentation due to basket compression. This procedure is repeated until all the calculi are removed. Vigorous flushing may be used to remove the smallest calculi. Leaving the cystoscope sheath in the urethra with the cranial end in the outflow tract while squeezing on the bladder can provide a conduit for small calculi to be flushed from the bladder. Laser lithotripsy uses a holmium:YAG laser as well as a cystoscope. Some urologists routinely perform laser lithotripsy of calculi in the bladder, ureters, and kidneys. Patient selection is critical because the time for fracture and extraction can be excessive for large or multiple calculi. Candidates for laser lithotripsy are patients that do not meet the criteria for other forms of endoscopic calculi removal. In general, laser lithotripsy appears to require a longer time for removal of calculi while resulting in a similar percentage of retained calculi as traditional cystotomy.10,11 Clinical studies of minilaparotomy cystotomy have fewer patients, but this technique appears to ensure a very favorable percentage of calculi removal.2,12

The basic scopes used to diagnose and remove calculi are the 2.7-mm rigid cystoscope (top) and the 2.5/2.8-mm flexible fiberoptic urethroscope (bottom). Cats and dogs weighing <5 kg frequently require a 1.9-mm cystoscope. The flexible scope is usually reserved for use in male dogs.

transvesicular cystoscopy require the use of a rigid cystoscope to examine the bladder and urethra and to remove calculi. A 2.7-mm cystoscope is generally used, except in cats and small dogs, for which a 1.9-mm cystoscope is preferred. After calculi are removed from the bladder and outflow tract, the urethra is examined with a rigid cystoscope (female dogs) or a 2.5/2.8-mm flexible fiberoptic urethroscope (male dogs; FIGURE 3). Urethral calculi in male dogs are removed by either retrograde flushing or a basket retrieval device passed beside the urethroscope during laparoscopic-assisted cystoscopy. Urethrostomy is rarely required to remove calculi obstructing the urethra just caudal to the os penis. Laparoscopic-assisted cystoscopy has been combined with other laparoscopic procedures such as liver biopsy or laparoscopic-assisted gastrointestinal foreign body removal. In laparoscopic-assisted cystoscopy, the laparoscope trocar is placed on the midline just caudal to the umbilicus to enable identification of the apex of the moderately distended urinary bladder. A second trocar, through which a 5-mm Babcock forceps can be passed to grasp the apex of the bladder, is then placed (FIGURE 4). The second trocar site is on the midline for female dogs, cats, and some male dogs, depending on the position of the prepuce in relationship to the

QuickNotes Endoscopy improves the ability to examine the urinary system for disease and the presence of more calculi.

CompendiumVet.com | October 2009 | Compendium: Continuing Education for Veterinarians®

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FIGURE 4 Laparoscopic-assisted cystotomy technique.

QuickNotes Setup for laparoscopic-assisted cystotomy. The monitor is to the rear of the patient. A right-handed surgeon stands to the patient’s left (top of illustration). The urinary bladder is mildly distended.

The bladder is secured to the patient, and a minicystotomy is made. A rigid cystoscope and retrieval devices are passed through the minicystotomy.

Calculi can be quickly grasped by placing a retrieval forceps alongside the cystoscope. Basket retrieval devices can also be used.

The cranial margin of the bladder is grasped and lifted to an extended trocar incision site. Insufflation pressure is decreased when the bladder is lifted.

Calculi can be removed with a variety of instruments, depending on the size and number of stones.

apex of the bladder. In most male dogs, the sec- just sufficient to secure it to the abdominal wall. ond trocar site is placed laterally (e.g., on the A variety of techniques can be used to keep the left side for a right-handed surgeon). The apex bladder firmly secured to the abdominal wall of the bladder is grasped with the forceps and and prevent urine contamination of the perilifted to the trocar site, which is extended as toneal cavity. In the most common technique, a minilaparotomy (FIGURE 4). If any bladder four quadrate attachments with interrupted lumen is cranial to the trocar site, inspection cruciate sutures are placed, and their long tags and removal of calculi from the cranial pouch are secured to drapes. Some surgeons prefer to of the bladder becomes difficult. The bladder is place a temporary continuous suture between not exteriorized, with the minilaparotomy being the bladder and skin.

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Compendium: Continuing Education for Veterinarians® | October 2009 | CompendiumVet.com

FIGURE 5 Equipment for intraoperative nephroscopy to remove renal calculi.

Intraoperative nephroscopy using a basket retrieval device can be an effective alternative, especially for calculi lodged in the proximal area of the ureter.

Once the bladder is securely sealed to the abdominal wall, a small cystotomy is performed and a rigid cystoscope (1.9 mm for cats and small dogs and 2.7 mm for larger dogs; FIGURE 4) is placed into the bladder. The bladder is lavaged in a fashion similar to that for transurethral cystoscopy. Some clinicians prefer to have a urethral catheter as an additional infusion source. The bladder and entire urethra of female dogs and the prostatic urethra of males are examined with the rigid cystoscope. Calculi can be removed with a variety of instruments, depending on the size and number of stones. Alligator forceps, 5-mm Babcock forceps, and arthroscopic grasping forceps are passed parallel to the cystoscope to grasp and retrieve calculi (FIGURE 4). Another removal technique is to use a wire basket retrieval instrument passed through the operating channel of the cystoscope. The entire assembly of cystoscope and forceps or basket retrieval device is removed with each stone and replaced into the bladder to retrieve the next. Once the larger calculi are removed, some

Intraoperative nephroscopy to remove renal calculi is similar to arthroscopy. A grasping device, such as an alligator forceps, is passed beside the cystoscope. Practice with inanimate models can markedly improve calculus retrieval skills.

smaller ones can be flushed from the bladder using urethral catheter flushing and surgical suction. The cystoscope is then advanced through the urethra in female dogs and cats. A 2.5- to 2.8mm flexible urethroscope can be passed from the bladder to the os penis in most male dogs and through the os penis in male dogs larger than 12 to 15 kg. Only the cranial portion of the urethra is examined in male cats. It is common to watch a urethral catheter pass around irregularly shaped calculi without feeling resistance to the catheter’s passage. In my experience, urethral strictures just proximal to the os penis from prior calculi obstruction and trauma are common in dogs. Knowledge of such strictures can justify a scrotal urethrostomy. After calculus removal and flushing, the cystotomy is closed in a single layer, using an appositional suture pattern, avoiding the mucosa. Greater omentum is sutured to the bladder closure. Keyhole transvesicular cystourethroscopy is performed in a similar fashion except that laparoscopy is not used and the apex of the

QuickNotes Practice with inanimate models can markedly improve calculus retrieval skills.

CompendiumVet.com | October 2009 | Compendium: Continuing Education for Veterinarians®

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FIGURE 6

Radiograph showing the renal calculi (arrows). These calculi were diagnosed 6 months before cystotomy to remove them.

QuickNotes Urinary calculi often recur.

One of the calculi is examined during nephroscopy.

bladder is grasped with surgical instruments passed through a small laparotomy.12 Again, it is critical that the cranial portion of the bladder be selected to avoid having bladder cranial to the cystotomy site. The remainder of the procedure is similar. Both laparoscopic-assisted and transvesicular cystoscopy techniques have been reported as being effective in the hands of the technique developers.2,12 Both allow the same excellent examination of the lower urinary tract, limit bladder trauma, limit urine contamination of the abdomen, and should increase the likelihood of complete removal of calculi.

Intraoperative Nephroscopy and Cystoscopy Rigid endoscopy during an open laparotomy causes minimal insult to the urinary system from the renal pelvis to the urethra,13 improves lighting, and increases magniﬁcation much more effectively than magnifying loupes and diode head lights. The optical space within the lumen of the renal pelvis and ureters is obtained as for cystoscopy, using saline infusion. The most frequent intraoperative use of endoscopy is to examine the renal pelvis and recesses when removing renoliths.13 The approach is similar to arthroscopy, with a scope being placed through a puncture in the greater curvature (lateral margin) of the kidney. Penetration of the pelvis is easy when the pelvis

482

The removed calculi. Recovery was uncomplicated.

Courtesy of Dr. Rawlings

Removal of renal calculi from a 12-year-old castrated Maltese.

is dilated. Calculi have been removed by using an alligator forceps placed beside a 30° scope or through a separate puncture to achieve triangulation or by using a basket retrieval device placed through the operating channel of the cystoscope (FIGURES 5 AND 6). Unlike nephrotomy, this minimally invasive retrieval of renal calculi using a scope placed through the renal pelvis does not require transient occlusion of renal vessels. The scope can also be passed through the proximal part of the ureter. When removing calculi endoscopically, the renal recesses must be thoroughly examined to ensure complete stone removal. The kidney perforations are closed by ﬁrmly apposing their sides or by placing small sutures in the capsule across the perforation. The scope can be used to differentiate between intraluminal calculi and mural calciﬁcation. I have also used an arthroscope to examine dilated ureters when removing ureteral calculi or performing a neocystostomy or ureterotomy. Cystoscopes and ureteroscopes have also been used to examine the lumen of the bladder and urethra during traditional laparotomy. Calculus removal via laparotomy in these cases usually involves major procedures such as nephrectomy or removal of stones from the kidney or ureter, which are not amenable to less invasive techniques. The cystoscope can be passed through a minicystotomy before a

Compendium: Continuing Education for Veterinarians® | October 2009 | CompendiumVet.com

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STATEMENT OF OWNERSHIP, MANAGEMENT AND CIRCULATION (Required by 39 U.S.C. 3685)

cystotomy is performed, for example, to determine the precise area before resection of an inﬂammatory polyp.14

Other Minimally Invasive Techniques Calculus removal treatments for dogs and cats are gradually being adapted from those used for people. Laser and electrohydraulic lithotripsy are already being used for cystic calculi in dogs and cats.3–11 Laser lithotripsy and ureteral stenting during ureteroscopy are routinely used for ureteral calculi in people; however, size is a limiting factor in small animals, especially cats and small dogs. In people, renal calculi are removed by percutaneous nephrolithotomy, ureterolithotomy, and cystolithotomy, typically involving lithotripsy, basketing, and flushing. Finally, extracorporeal shock wave lithotripsy is an alternative to reduce calculus size so that urine flow can flush the fragments.13,15

Postoperative Patient Management Case management must be directed to the patient’s needs. At least one lateral radiograph should be taken after calculus removal while the patient is anesthetized to ensure that residual radiopaque

calculi are not present. Appropriate fluid management helps maintain renal function and flush residual blood and calculi fragments. Although laparoscopic procedures are less invasive than traditional surgery, pain medication is routinely used. Typical protocols include administering opioids during the initial recovery period and either NSAIDs or opioids for the first few days after calculus removal. Bupivacaine can be infused into the urethra for additional transient analgesia. Dietary management to reduce calculus formation is usually delayed until the patient is fully recovered and the final calculi analysis obtained. Nutritional therapy soon after surgery should focus on supporting early healing. Urinary calculi often recur. Patients with a history of calculus removal must be closely monitored by the owner and veterinarian. Those with a history of urinary tract infection must have regular urinalysis and, if indicated, urine cultures. When feasible, dietary management should be considered. Dogs and cats in which calculi recur despite good medical management are candidates for ultrasonography studies every 4 to 6 months. Radiography can also be considered for radiopaque calculi.

References 1. Ling GV, Thurmond MC, Choi YK, et al. Changes in proportion of canine urinary calculi composed of calcium oxalate or struvite in specimens analyzed from 1981 through 2001. J Vet Intern Med 2003;17:817-823. 2. Rawlings CA, Barsanti JA, Mahaffey MB, Canalis C. Use of laparoscopic-assisted cystoscopy for removal of calculi in dogs. JAVMA 2003;222:759-761. 3. Senior DF. Electrohydraulic shock-wave lithotripsy for experimental canine struvite bladder stone disease. Vet Surg 1988;22:213-219. 4. Adams LG, Senior DF. Electrohydraulic and extracorporeal shock-wave lithotripsy. Vet Clin North America Small Anim Pract 1999;29:293-302. 5. Lane IF. Lithotripsy: an update on urologic applications in small animals. Vet Clin North Am Small Anim Pract 2004;34(4):1011-1025. 6. Davidson EB, Ritchey JW, Higbee RD, et al. Laser lithotripsy for treatment of canine uroliths. Vet Surg 2004;33:56-61. 7. Grant DC, Were SR, Gevedon ML. Holmium:YAG laser lithotripsy for urolithiasis in dogs. J Vet Intern Med 2008;22(3):534-539. 8. Adams L, Berent A, Moore A, Bagley D. Laser lithotripsy for the removal of uroliths in 73 dogs. JAVMA 2008;232(7):1026-1034.

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9. Defarges A, Dunn M. Use of electrohydraulic lithotripsy in 28 dogs with bladder and urethral calculi. J Vet Intern Med 2008;22(6):1267-1273. 10. Bevan JM, Lulich JP, Albasan H, Osborne CA. Comparison of laser lithotripsy and cystotomy for the management of dogs with urolithiasis. JAVMA 2009;234:1286-1294. 11. Lulich JP, Osborne CA, Albasan H, et al. Efficacy and safety of laser lithotripsy in fragmentation of urocystoliths and urethroliths for removal in dogs. JAVMA 2009;234:1279-1285. 12. Runge JJ, Mayhew P, Berent A, et al. Keyhole transvesicular cystourethroscopy for the retrieval of cystic and urethral calculi in dogs and cats. 43rd Annu Meet Am Coll Vet Surg 2008. 13. McCarthy TC. Otheroscopies. In: McCarthy TC, ed. Veterinary Endoscopy for the Small Animal Practitioner. St Louis: Elsevier Saunders; 2005:423-445. 14. Rawlings CA. Resection of inflammatory polyps in dogs using laparoscopic-assisted cystoscopy. JAAHA 2007;43:1-5. 15. Block G, Adams LG, Widmer WR, et al. Use of extracorporeal shock wave lithotripsy for treatment of nephrolithiasis and ureterolithiasis in five dogs. JAVMA 1996;208(4):531.

Compendium: Continuing Education for Veterinarians® | October 2009

1. Title of Publication: Compendium: Continuing Education For Veterinarians, 2. Publication Number: 1940-8307, 3. Date of Filing: October 1, 2009, 4. Frequency of Issue: Monthly, 5. Number of Issues Published Annually: 12, 6. Annual Subscription Price: $79, 7. Complete Mailing Address of Known Ofﬁce of Publication: Veterinary Learning Systems, 780 Township Line Road, Yardley, Bucks County, PA 19067, Contact Person: Christine Polcino, Telephone: 267-685-2419, 8. Complete Mailing Address of Headquarters or General Business Ofﬁce of the Publisher: Veterinary Learning Systems, 780 Township Line Road, Yardley, PA 19067, 9. Full Names and Complete Mailing Addresses of Publisher, Editor, and Managing Editor—Publisher: Derrick Kraemer, Veterinary Learning Systems, 780 Township Line Road, Yardley, PA 19067; Editor: Tracey Giannouris, 780 Township Line Road, Yardley, PA 19067; Managing Editor: Kirk McKay, 780 Township Line Road, Yardley, PA 19067, 10. Owner: Veterinary Learning Systems/MediMedia USA, 780 Township Line Road, Yardley, PA 19067, 11. Known Bondholders, Mortgagees, and Other Security Holders Owning or Holding 1 Percent or More of Total Amount of Bonds, Mortgages or Other Securities: None, 12. Tax Status – Has Not Changed During Preceding 12 Months, 13. Publication Title – Compendium: Continuing Education For Veterinarians, 14. Issue Date for Circulation Data Below: July 2009, 15. Extent and Nature of Circulation—15a.Total Number of Copies (Net Press Run) - Average Number Copies Each Issue During Preceding 12 Months: 53,957, Actual Number Copies of Single Issue Published Nearest to Filing Date: 50,631, 15b(1) Mailed Outside-County Paid Subscriptions Stated on PS Form 3541 - Average Number Copies Each Issue During Preceding 12 Months: 5,631, Actual Number Copies of Single Issue Published Nearest to Filing Date: 4,785, 15b(3). Paid Distribution Outside the Mail Including Sales Through Dealers and Carriers, Street Vendors, Counter Sales, and other Paid Distribution Outside USPS - Average No. Copies Each Issue During Preceding 12 Months: 0, Actual No. Copies of Single Issue Published Nearest to Filing Date: 0, 15c. Total Paid Distribution - Average No. Copies Each Issue During Preceding 12 Months: 5,631, Actual No. Copies of Single Issue Published Nearest to Filing Date: 4,785, 15d(1). Free or Nominal Rate Outside-County Copies Included on PS Form 3541 - Average No. Copies Each Issue During Preceding 12 Months: 45,646, Actual No. Copies of Single Issue Published Nearest to Filing Date: 43,935, 15d(4). Free or Nominal Rate Distribution Outside the Mail - Average No. Copies Each Issue During Preceding 12 Months: 0, Actual No. Copies of Single Issue Published Nearest To Filing Date: 0, 15e. Total Free or Nominal Rate Distribution - Average No. Copies Each Issue During Preceding 12 Months: 45,646, Actual No. Copies of Single Issue Published Nearest to Filing Date: 43,935, 15f. Total Distribution - Average No. Copies Each Issue During Preceding 12 Months: 51,277, Actual No. Copies of Single Issue Published Nearest to Filing Date: 48,720, 15g. Copies not Distributed - Average No. Copies Each Issue During Preceding 12 Months: 2,680, Actual No. Copies of Single Issue Published Nearest to Filing Date: 1,911, 15h. Total - Average No. Copies Each Issue During Preceding 12 Months: 53,957, Actual No. Copies of Single Issue Published Nearest to Filing Date: 50,631, 15i. Percent Paid - Average No. Copies Each Issue During Preceding 12 Months: 11%, Actual No. Copies of Single Issue Published Nearest to Filing Date: 10%, 16. This Statement of Ownership will be printed in the October 2009 issue of this publication. 17. I certify that the statements made by me above are correct and complete: Derrick Kraemer, Publisher.

Product Forum Hyperthyroidism Treatment

Joint Supplement

Dechra Veterinary Products has released the newest size of its FDA-approved Felimazole coated tablets. The tablets, now commercially available in 2.5and 5-mg sizes, contain the active ingredient methimazole, the most common drug used to treat hyperthyroidism in cats. The new, smaller tablets offer an option to veterinarians that does not require splitting for appropriate dosing.

FruitFast has introduced its CherryFlex for Dogs Softgel fruit supplements. Made from whole fruit, including the skin and pulp, CherryFlex for Dogs Softgels have a great-tasting natural beef ﬂavor without preservatives, by-products, or ﬁllers. Designed to help dogs maintain healthy joint function, the CherryFlex for Dogs special formulation is available in 60-count bottles.

Dechra Veterinary Products | 913-327-0015 | www.dechra-us.com

Brownwood Acres Food Inc. | 877-591-3101 www.brownwoodacres.com

Ultrasound

Planning Software

Aloka Ultrasound has announced veterinary clinical enhancements to its ProSound Alpha 7. The relevant clinical applications for veterinary medicine include trapezoidal scanning for wider aperture for vascular imaging, a high-deﬁnition, extended ﬁeld of view to create panoramic images of entire anatomic structures; and adaptive image processing. The Alpha 7 has an ergonomic design, is the smallest and lightest system in its class, and now consumes 40% less electricity.

Vetel Diagnostics has introduced OrthoViewVET, a preoperative planning and templating solution for veterinary surgeons. This software offers advanced scaling and templating tools for application with all veterinary patients, including small animals, horses, and exotic and zoo animals. The software gives veterinarians the ability to perform surgery with increased accuracy and ease while saving time. OrthoViewVET analyzes the orthopedic hardware by each manufacturer so the surgeon can superimpose the hardware on a radiograph and perform a virtual surgery. The fracture management module also features on-screen visualization of plate bending.

Aloka, Inc. | 800-872-5652 | www.alokavet.com

Vetel Diagnostics | 800-458-8890 | www.veteldiagnostics.com

Portable X-Ray The ImageVet Portable offers portable x-ray capability without sacriﬁcing image quality. This lightweight, handheld unit is easy to carry, easy to store, and simple to position for superior-quality radiographs. A large battery capacity allows the device to be used for more than 100 examinations on a single charge. It comes with a comfortable tie that can be adjusted to ﬁt the user’s hand, enhancing mobility. AFP Imaging | 800-592-6666 | www.afpimaging.com

Clipper The Libretto super clipper, from Lister Shearing Equipment, offers users three power options: a 12-V (Liberty clipper) power pack (4-hour running time), a wall adapter, or a 12-V vehicle cord. The clipper has a small body and quiet running motor for hardto-reach and sensitive areas, yet has a high clipper speed, making it capable of a full clip when required. The Libretto comes with a carrying case and accessories. Wahl Clipper Corporation | 800-767-9245 | www.wahlanimal.com The product information presented here is provided by the manufacturers and does not reﬂect endorsement by Compendium.

Index to Advertisers For free information about products advertised in this issue, e-mail the product names to productinfo@compendiumvet.com. Company

Product

Page

Abbott Animal Health

Fluid Therapy

445 (US only)

Andis Company

Grooming Tools

449

Banﬁeld, the Pet Hospital

We Believe in Vets

Inside back cover

Bayer Animal Health

Advantage and K9 Advantix

467

Profender

447, 448

resQ

453

Hill’s Pet Nutrition

Prescription Diet r/d Canine

Inside front cover (Canada only)

Northgate Veterinary Supply

Glass cage doors and rod gates

486

PetRays

Free Telemedicine Trial

486

VCA Animal Hospitals

The Latest Technology

461

VCA Antech

Hospital Purchase Program

Inside front cover (US only)

Veterinary Learning Systems

Veterinary Technician

483

Vetstreet

Pet Portals

458, 459

Western Veterinary Conference

2010 Conference

Back cover

WhereTechsConnect.com

Job Marketplace

486

CompendiumVet.com | October 2009 | Compendium: Continuing Education for Veterinarians®

485

3 CE CREDITS

CE Article 2

In collaboration with the American College of Veterinary Surgeons

Vacuum-Assisted Wound Closure: Application and Mechanism of Action ❯❯ Kristin A. Kirkby, DVM, MS, CCRT, DACVS ❯❯ Jason L. Wheeler, DVM, MS, DACVS ❯❯ James P. Farese, DVM, DACVS ❯❯ Gary W. Ellison, DVM, MS, DACVS

❯❯ Nicholas J. Bacon, MA, VetMB, DECVS, MRCVS, DACVS ❯❯ Colin W. Sereda, DVM, MS, DACVS ❯❯ Daniel D. Lewis, DVM, DACVSa University of Florida

Abstract: Vacuum-assisted closure (VAC) is a wound management therapy that creates local negative pressure over a wound bed to promote healing. Beneﬁts of VAC therapy include removal of ﬂuid from the extravascular space, improved circulation, enhanced granulation tissue formation, increased bacterial clearance, and hastening of wound closure. This article describes the mechanism of action of VAC therapy, reviews application techniques, and lists potential complications and contraindications.

At a Glance Equipment and Application Page 568

Beneﬁcial Effects and Mechanism of Action Page 572

Complications and Contraindications Page 576

aDr.

Lewis discloses that he has received ﬁnancial support from Arthrex Vet Systems and Imex Veterinary.

568

acuum-assisted closure (VAC) is a and promoting abscess formation.1,4 VAC noninvasive, active wound manage- therapy is applicable for the treatment of ment system that subjects a wound several wound types (BOX 1). A VAC system consists of several essenbed to subatmospheric pressure within a closed environment. Within this closed, tial elements: sterile open-cell polyurethane negative-pressure environment, VAC ther- foam (pore size: 400 to 600 μm), plastic apy removes fluid from the extravascular egress tubes, occlusive plastic adhesive space, improves circulation, and enhances film, suction tubing, a collection reservoir, the proliferation of granulation tissue.1–4 and an adjustable suction pump capable This article describes the necessary equip- of intermittent or continuous negative ment for, and method of applying, VAC pressures ranging from –50 to –200 mm therapy; reviews the mechanism of action Hg. These components are commercially and benefits; and describes contraindica- available (Kinetic Concepts, Inc. [KCI], San tions and complications. Antonio, TX; Smith and Nephew, London, England). Additional supplies that we have Equipment and Application found useful in applying VAC therapy Basic wound care principles must be fol- include a skin stapler, adhesive paste, and lowed before VAC therapy is initiated. adhesive spray (TABLE 1). Patients are hosProper debridement of devitalized tissue is pitalized for the duration of VAC therapy essential to eliminate any potential nidus (usually 3 to 7 days) and require frequent for bacterial growth and to allow suc- monitoring. An airtight seal is essential to maintain cessful wound closure after VAC therapy.4 Incomplete wound debridement before the continuous negative pressure and prevent application of VAC therapy may result in desiccation of the underlying tissue.1 In the proliferation of granulation tissue over dogs and cats, the hair on the skin adjacent necrotic tissue, delaying wound healing to the wound must be clipped to facilitate

Compendium: Continuing Education for Veterinarians® | December 2009 | Vetlearn.com

JOHN WAS 58 WHEN HE THOUGHT ABOUT RETIREMENT.

THEN HE THOUGHT ABOUT WHO WOULD BUY HIS PRACTICE. VCA Animal Hospitals

PLEASE CONTACT US TODAY.

For more than 20 years, VCA’s hospital purchase programs have given practice owners the freedom to live their lives with peace of mind. More than 475 hospitals in 41 states have joined the VCA family. You have worked hard to create a legacy. VCA’s goal is to continue the success you created. Please contact us if you have a veterinary practice in excess of $1.25 million dollars in annual revenue with 3 or more veterinarians. If you are thinking of selling your practice call VCA. If your hospital is really close to an existing VCA location a merger might be right for you.

Darin Nelson Senior Vice President Development 800-550-2388 (office) 949-228-2525 (mobile) darin.nelson@vcamail.com Neil Tauber Senior Vice President 310-571-6504 (office) 310-890-0444 (mobile) neil.tauber@vcamail.com www.vcaantech.com

FREE

CE Wound Closure Therapy

QuickNotes Basic wound care principles must be followed for all wounds before the application of VAC therapy.

MORE ON THE WEB A companion article on clinical applications of vacuum-assisted wound closure will be published in March 2010.

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creation of this seal. The foam should be cut to conform to the shape of the wound and placed, fully expanded, directly within the wound so that it is in contact with the entire wound surface, especially the deep margins1,2,4 (FIGURE 1). A plastic, fenestrated egress tube or polyvinyl (red rubber) catheter (10 to 14 Fr) with several additional 2- to 3-mm fenestra-tions is then tunneled into a hole cut into the foam or placed between two pieces of foam.. To avoid pressure necrosis in tissue adjacent to the fenestrations, the egress tube should not be in direct contact with the wound bed.. When the foam and plastic tubing are in place,, the foam can be secured to the wound mar-gins using skin staples (FIGURE 1). To establish an airtight seal, we have found it helpful to apply adhesive spray and a ring of adhesive paste to the skin surrounding the wound before covering the foam and tubing with the adhesive plastic film. The film should extend several centimeters beyond the wound margins (FIGURE 1). The egress suction tube is attached to standard suction tubing and a collection reservoir, which is in turn connected to the vacuum pump with additional suction tubing. We use and recommend continuous suction. The continuous negative-pressure setting most commonly used during VAC therapy is –125 mm Hg.1–6 Initial animal studies showed improved blood flow and granulation tissue formation with intermittent suction (5 minutes on, 2 minutes off)2; however, human patients reported more discomfort when suction was applied intermittently than when it was continuous.1 In our experience, veterinary patients tolerate continuous suction well and do not require pain medication specifically for VAC therapy. When VAC therapy is used postoperatively over a closed incision to prevent seroma and edema formation, a lower negative-pressure setting of –50 mm Hg has been advocated.4 When VAC therapy is used in this manner, the foam can be cut and placed directly over the incision or, if the incision is on a limb, wrapped around the circumference of the limb. If the foam is wrapped circumferentially around a limb, it is essential to cover the entire limb distal to the incision, including the paw, with the foam to prevent a tourniquet effect.

Surgical Views is a collaborative series between the American College of Veterinary Surgeons (ACVS) and Compendium. Upcoming topics in this series include conventional foreign object removal and suspensory ligament rupture. All Surgical Views articles are peer-reviewed by ACVS diplomates. To locate a diplomate, ACVS has an online directory that includes practice setting, species emphasis, and research interests (acvs.org/VeterinaryProfessionals/FindaSurgeon).

When suction is applied, the foam should visibly collapse within the wound and take on a “raisin” appearance beneath the adhesive ﬁlm (FIGURE 1). The KCI and Smith and Nephew negative-pressure wound care units are equipped with alarm systems to detect air leakage. If one of these pumps is not being used, the appearance and texture of the foam must be checked frequently to ensure that there is no loss of suction. If the airtight seal is lost, measures must be taken to restore the vacuum immediately.

Compendium: Continuing Education for Veterinarians® | December 2009 | Vetlearn.com

Indications for VAC Therapya BOX 1

Large, open, contaminated wounds Skin avulsions Degloving injuries Abdominal and thoracic wounds (e.g., laparotomy surgical sites, open thoracic wounds) Surgical dehiscence Chronic nonhealing wounds Prevention of postoperative seroma and edema Bolster for skin grafts Myofascial compartment syndrome a

Our experience with the use of VAC therapy for these indications will be detailed in a companion article in March 2010.

Your Clients. Their Dogs. Our Thyro-Tabs. ®

(levothyroxine sodium tablets, USP)

Our combination of stability, quality and dependability has produced successful results for nearly three decades. Today, with treatment lines for dogs, horses, and humans, LLOYD, Inc. supplies more levothyroxine sodium to the market than anyone else in the country. Nine dosing strengths. Three package options. One source. Call for a free starter sample.

Caution: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Indications: For use in dogs for correction of conditions associated with low circulating thyroid hormone (hypothyroidism). Dosages: The initial recommended daily dose is 0.1 to 0.2 mg/10 pounds (4.5 kg) body weight in single or divided doses. Dosage is then adjusted by monitoring the T4 blood levels of the dog every four weeks until an adequate maintenance dose is established. Administration: Thyro‑Tabs® may be administered orally or placed in the pet’s food. Warnings: The administration of levothyroxine sodium to dogs to be used for breeding purposes or in pregnant bitches has not been evaluated. There is evidence to suggest that administration to pregnant bitches may in some instances affect the normal development of the thyroid gland in unborn pups. How Supplied: 0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, and 1.0 mg tablets in 28, 120, and 1,000 count. READ PACKAGE INSERT FOR COMPLETE DIRECTIONS

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CE Wound Closure Therapy Components Recommended for Application of VAC Therapy and Approximate Pricea TABLE 1

Component Sterile open-cell polyurethane foam (pore size: 400–600 μm) Plastic egress tube

QuickNotes VAC therapy increases wound circulation, accelerates granulation tissue formation, and removes excess ﬂuid from the extravascular space.

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Costb $8.00/8" × 12" sheet $8.75

Occlusive plastic adhesive ﬁlm

$23.25

Skin staples

$23.00

Adhesive spray

$3.75c

Adhesive paste

$22.95

Suction tubing and collection reservoir

$20.00

Suction pump capable of continuous negative pressure

$54.00d

a Essential items are in bold. bPrices listed are based on costs charged to clients at the University of Florida

Veterinary Medical Center. c This cost is not billed to clients because one container can be used for

approximately 20 patients. d This is a daily fee assessed for continuous suction through either central

suction or a VAC machine.

The frequency of VAC bandage changes depends on the characteristics of the wound. VAC bandages are typically changed every 48 to 72 hours,3–5 although initial management of traumatic or highly contaminated wounds may require the bandage to be changed every 24 hours to allow adequate debridement.5,7,8 Culture and sensitivity testing and administration of appropriate antibiotic therapy are indicated for infected wounds. If VAC bandages are left in place for more than 4 to 5 days, granulation tissue may grow into the pores of the open-cell foam, requiring surgical removal of the foam bandage.1 Modiﬁcations to traditional VAC therapy have been introduced to treat highly infected wounds or wounds with resistant infections, including silver-impregnated foam (V.A.C. Granufoam Silver Dressing, KCI) and a system that combines negative-pressure wound therapy and antibiotic instillation (V.A.C. Instill, KCI).5 Early results of the use of these systems in highly infected wounds are promising, although no studies of their use been conducted in dogs.8–12 In dogs and cats, bandages can usually be changed with patients under heavy sedation.2 If

VAC therapy is used for long periods of time and multiple bandage changes are performed, the plastic adhesive film can be incised directly over the foam, which can then be removed through the fenestration in the film. Leaving the margins of the original film adhered to the skin reduces skin irritation and minimizes the discomfort experienced during bandage changes by avoiding pulling the film away from the skin. New adhesive film sheets are then placed over the previously applied bandage.7

Beneficial Effects and Mechanism of Action The uniform negative pressure applied to the wound bed by VAC therapy has several beneficial effects, including decreased interstitial edema, increased tissue blood flow, accelerated granulation tissue formation, increased bacterial clearance, and hastened wound closure.1,2 VAC therapy enhances the formation of granulation tissue by increasing capillary blood flow velocity, stimulating endothelial cell proliferation and angiogenesis, narrowing endothelial spaces, and restoring capillary basement membrane integrity.12 Decreased capillary permeability results in reduced edema formation, and the closed, negative-pressure system removes excess interstitial fluid, resulting in decreased local interstitial pressure and restoration of blood flow to previously collapsed vessels.2 An additional mechanism by which VAC therapy increases granulation tissue formation is through mechanical stresses exerted on the wound environment. VAC therapy mechanically stimulates cells by exerting tensile forces on the surrounding tissues.4 The concept that tissues respond to applied forces has long been recognized in relation to bone physiology (Wolff’s law) and is the basis of the Ilizarov technique for distraction osteogenesis.13 In wounds treated with VAC therapy, the cytoskeleton of cells exposed to subatmospheric pressure is altered, resulting in the release of intracellular second messengers and upregulation of cell proliferation.14 VAC therapy is also postulated to increase granulation tissue formation through the removal of substances (e.g., degradative enzymes, proteases, collagenases) that negatively affect wound healing.3 The ability of VAC therapy to enhance bacterial clearance has been debated.2,15–17 Initial animal studies comparing the bacterial clearance of VAC therapy with that of daily saline wet-

Compendium: Continuing Education for Veterinarians® | December 2009 | Vetlearn.com

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CE Wound Closure Therapy FIGURE 1 Method of VAC bandage application.

(A) A large thermal burn on the dorsum of an adult boxer. (B) One week after injury, the eschar has been debrided, leaving a large open wound. Polyurethane open-cell foam is placed within the wound.

(C) The margins of the wound are advanced and secured to the foam using skin staples. A polyvinyl catheter has been tunneled into the foam and exits the foam at the upper left wound margin. This catheter is connected to standard suction tubing, which is then connected to a collection reservoir and suction pump. (D) A ring of adhesive paste has been placed around the wound margins, the foam and surrounding skin have been sprayed with adhesive spray, and adhesive film has been placed over the foam and surrounding skin. Negative pressure (–125 mm Hg) has been applied to the bandage, and the foam has contracted beneath the film, taking on a raisinlike appearance and texture.

Approximately 6 weeks after the original injury, the wound is closed and healing appropriately. This wound required approximately 10 days of VAC therapy.

to-dry bandages showed a drop in quantitative bacterial counts in VAC-treated wounds and a peak in bacterial counts in the control group by day 5.2 However, clinical studies evaluating wounds treated with VAC therapy in human patients have failed to show a signiﬁcant reduction in total bacterial counts.16,17 Irrespective of

574

whether bacterial numbers are reduced, VAC therapy is able to improve a wound’s resistance to bacterial overgrowth through the creation of a healthier wound environment.16 VAC therapy is not, however, a substitute for proper wound management, and wounds must be appropriately debrided before VAC therapy application.

Compendium: Continuing Education for Veterinarians® | December 2009 | Vetlearn.com

Rekindle the warmth of friendship. Atopic dermatitis can disrupt even the best relationships. Restore their closeness by prescribing ATOPICA (Cyclosporine Capsules, USP) MODIFIED. Its targeted action gives dogs lasting comfort without the serious health risks associated with steroids. What could be better than bringing friends back together? As with all drugs, side effects may occur. In a field study, the most common side effects were gastrointestinal signs. Gingival hyperplasia and papillomas may also occur during the initial dosing phase. ATOPICA is a systemic immunosuppressant that may increase the susceptibility to infection. ATOPICA is not for use in reproducing dogs or dogs with a history of neoplasia. ®

See Page 576 for Product Information Summary

ATO090302A

Brief Summary: For full product information see product insert. Caution: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Description: ATOPICA (cyclosporine capsules, USP) MODIFIED is an oral form of cyclosporine that immediately forms a microemulsion in an aqueous environment. Indications and Usage: ATOPICA is indicated for the control of atopic dermatitis in dogs weighing at least 4 lbs body weight. Dosage and Administration: The initial daily dose of ATOPICA is 5 mg/kg/day (3.3-6.7 mg/kg/day) as a single daily dose for 30 days. Following this initial daily treatment period, the dose of ATOPICA may be tapered by decreasing the frequency of dosing to every other day or two times a week, until a minimum frequency is reached which will maintain the desired therapeutic effect. ATOPICA should be given at least one hour before or two hours after a meal. If a dose is missed, the next dose should be administered (without doubling) as soon as possible, but dosing should be no more frequent than once daily. See Product Insert for dosing chart. Contraindications: ATOPICA is contraindicated for use in dogs with a history of neoplasia. WARNINGS: ATOPICA (cyclosporine) is a potent systemic immunosuppressant that may increase the susceptibility to infection and the development of neoplasia. Human Warnings: Not for human use. Keep this and all drugs out of reach of children. For use only in dogs. Precautions: Gastrointestinal problems and gingival hyperplasia may occur at the initial recommended dose. ATOPICA should be used with caution with drugs that affect the P-450 enzyme system. Simultaneous administration of ATOPICA with drugs that suppress the P-450 enzyme system, such as ketoconazole, may lead to increased plasma levels of cyclosporine. The safety and effectiveness of ATOPICA has not been established in dogs less than 6 months of age or less than 4 lbs body weight. ATOPICA is not for use in breeding dogs, pregnant or lactating bitches. Since the effect of cyclosporine use on dogs with compromised renal function has not been studied ATOPICA should be used with caution in dogs with renal insufficiency. There have been reports of convulsions in human adult and pediatric patients receiving cyclosporine, particularly in combination with high dose methylprednisolone. Killed vaccines are recommended for dogs receiving ATOPICA because the impact of cyclosporine on the immune response to modified live vaccines is unknown. As with any immunomodulation regimen, exacerbation of sub-clinical neoplastic conditions may occur. Adverse Reactions: A total of 265 dogs were included in the field study safety analysis. One hundred and eleven (111) dogs were treated with placebo for the first 30 days. For the remainder of the study, all dogs received ATOPICA capsules. Four dogs withdrew from the study after vomiting. One dog each withdrew from the study after diarrhea; vomiting, diarrhea and pruritus; vomiting, depression and lethargy; lethargy, anorexia and hepatitis; gingival hyperplasia, lethargy, polyuria/polydipsia and soft stool; seizure; sebaceous cyst; pruritus; erythema; or otitis externa respectively. Vomiting (30.9%) and diarrhea (20.0%) were the most common adverse reactions occurring during the study.In most cases, signs spontaneously resolved with continued dosing. In other cases, temporary dose modifications (brief interruption in dosing, divided dosing, or administration with a small amount of food) were employed to resolve signs. Persistent otitis externa (6.8%), urinary tract infections (3.8%), anorexia (3.0%), gingival hyperplasia (2.3%), lymphadenopathy (2.3%) and lethargy (2.3%) were the next most frequent adverse events observed. Gingival hyperplasia regressed with dose tapering. Owners of four dogs reported seizures while dogs were receiving ATOPICA. In one dog, seizures were the result of a brain tumor diagnosed one month into the study. Another dog experienced seizures before and after the study. The following clinical signs were reported in less than 2% of dogs treated with ATOPICA in the field study: constipation, flatulence, Clostridial organisms in the feces, nausea, regurgitation, polyuria/ polydipsia, strong urine odor, proteinuria, pruritus, erythema/ flushed appearance, pyoderma, sebaceous adenitis, crusty dermatitis, excessive shedding, coarse coat, alopecia, papillomas, histiocytoma, granulomatous mass or lesion, cutaneous cyst, epulis, benign epithelial tumor, multiple hemangioma, raised nodule on pinna, seizure, shaking/trembling, hind limb twitch, panting, depression, irritability, hyperactivity, quieter, increased light sensitivity, reluctance to go outside, weight loss, hepatitis. Clinical Pathology Changes: During the study, some dogs experienced changes in clinical chemistry parameters while receiving ATOPICA, as follows: elevated creatinine (7.8%), hyperglobulinemia (6.4%), hyperphosphatemia (5.3%), hyperproteinemia (3.4%), hypercholesterolemia (2.6%), hypoalbuminemia (2.3%), hypocalcemia (2.3%) and elevated BUN (2.3%). Post-approval Experience: Neoplasms have been reported in dogs taking ATOPICA, including reports of lymphosarcoma and mast cell tumor. It is unknown if these were preexisting or developed de novo while on ATOPICA. In post-approval drug experience reporting the following additional adverse reactions have been associated with ATOPICA administration in dogs: vomiting, diarrhea, depression/ lethargy, anorexia, pruritus, liver enzyme elevations, trembling, convulsions, polydipsia, polyuria, weight loss, hyperactivity, nervousness, neoplasia. To report suspected adverse reactions or for technical assistance, call 1-800-332-2761. Manufactured for: Novartis Animal Health US, Inc. Greensboro, NC 27408, USA NADA 141-218, Approved by FDA ©2009 Novartis Animal Health US, Inc. ATOPICA is a registered trademark of Novartis AG. NAH/ATO-GC/BS/5 07/08

FREE

CE Wound Closure Therapy Another advantage associated with the use of VAC therapy is the acceleration of wound closure.17 The mechanical forces and improved granulation tissue formation hasten wound contraction, resulting in earlier closure.17 The reduction in time needed to achieve a healthy wound bed, along with the need for fewer bandage changes under sedation, may offer cost savings for VAC therapy compared with conventional dressings that must be changed once or twice daily.17

Complications and Contraindications Complications associated with VAC therapy tend to be minor and easily managed. In our experience, the most common complication is the loss of the airtight seal, which can often be corrected by adding an additional layer of adhesive film. Local dermatitis associated with the bandage is also common but tends to be self-limiting. A significant complication resulted from leaving a VAC therapy dressing in place for 5 days. Granulation tissue grew into the pores in the open-cell foam and necessitated surgical excision of the foam to completely remove the polyurethane fibers. Few complications have been reported in human patients undergoing VAC therapy.5 The most common complication is mild skin irritation from contact with the foam.1,4 Two cases of toxic shock syndrome associated with VAC therapy use have been reported.18 Additionally, chronic complications may result from pieces of foam being left within the wound.5 VAC therapy should be used with caution in hemodynamically unstable patients because

large volumes of ﬂuid can be removed during treatment.3,4 There are several contraindications to VAC therapy. The VAC system has a limited ability to debride wounds, and it will not remove devitalized or necrotic tissue. Thus, VAC therapy should not be used in lieu of proper surgical debridement.1,4 The treatment of osteomyelitis with the VAC system alone is also contraindicated.4,19 The VAC therapy system should not be used in wounds contaminated with malignant neoplastic cells because the application of the VAC therapy bandage will likely increase blood ﬂow and stimulate cellular proliferation within the wound bed.1,4 Finally, care should be taken when placing VAC therapy dressings near exposed arteries and veins. It is possible for the foam to erode through exposed vessels, resulting in extensive blood loss.4,5 Similarly, VAC therapy dressings should be used with caution in patients with coagulopathies or active bleeding.4,5

Conclusion VAC therapy increases local blood ﬂow and enhances granulation tissue formation in wounds, accelerates wound contraction, and removes excessive ﬂuid from wounds. After adequate debridement, VAC therapy can be applied to a wide variety of wounds.

ON THE WEB

The references for this article are available at Vetlearn.com.

CE TEST 2 This article qualiﬁes for 3 contact hours of continuing education credit

3 CE CREDITS

from the Auburn University College of Veterinary Medicine. Subscribers must take individual CE tests online and get real-time scores at Vetlearn.com. Those who wish to apply this credit to fulﬁll state relicensure requirements should consult their respective state authorities regarding the applicability of this program.

576

Compendium: Continuing Education for Veterinarians® | December 2009 | Vetlearn.com

Index to Advertisers For free information about products advertised in this issue, e-mail the product names to productinfo@CompendiumVet.com. Company

Product

Page #

AAHA

Long Beach 2010 Conference

573

Abbott Animal Health

SevoFlo

544, 545

Antech Diagnostics

FastPanel PCR

551

Banﬁeld, the Pet Hospital

We Believe in Vets

541 (US only)

Bayer HealthCare Animal Health

Advantage Multi for Dogs

552, 553

resQ

539

“A Perfect Fit”

548–549

Boehringer Ingelheim Vetmedica

ProZinc

555, 556

Prescription Diet j/d Canine

Inside front cover (Canada only)

Intervet/Schering-Plough Animal Health

Canine Inﬂuenza Vaccine

Back cover

Lloyd, Inc.

Thyro-Tabs

571

Northgate Veterinary Supply

Glass cage doors and rod gates

578

Novartis Animal Health

Atopica

575, 576

P&G Pet Care

NAVC/WVC Symposia

565

Prostora MAX

563 Inside front cover (US only)

Hill’s Pet Nutrition

Sound-Eklin

Veterinary Imaging

VCA Antech

Hospital Purchase Program

569

Vet-Stem, Inc.

Credentialing Courses

Inside back cover

Veterinary Learning Systems

Vetlearn.com

567, 577

Vetstreet

Pet Portals

558, 559

Western Veterinary Conference

2010 Conference

561

WhereTechsConnect.com

Job Marketplace

578

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Understanding

Behavior About This Column Behavior problems are a signiﬁcant cause of death (euthanasia) in companion animals. While most veterinary practices are necessarily geared toward the medical aspect of care, there are many opportunities to bring behavior awareness into the clinic for the beneﬁt of the pet, the owner, and ourselves. This column acknowledges the importance of behavior as part of veterinary medicine and speaks practically about using it effectively in daily practice.

Behavior Assessment: The First Appointment* ❯❯ Sharon L. Crowell-Davis, DVM, PhD, DACVB,a The University of Georgia *The ﬁrst article in this series on patient evaluation, “Behavior Assessment: History Forms and Interviews,” was published in the December 2008 issue of Compendium and is available at CompendiumVet.com.

s described in the first article in this series, gaining an accurate description of a pet’s undesirable behavior is crucial to correctly diagnosing the cause of the behavior. However, more information is needed than a good description. The circumstances in which the behavior occurs must also be clarified, along with any treatments the owner has already attempted, either alone or with advice from a veterinarian, animal trainer, or other source. The pet’s signalment, environment, and background may all affect its behavior and should be discussed with the owner. Some of this information can be gathered in advance through the use of history forms; some may be better obtained through interviews and conversation with the owner during the first appointment devoted specifically to the behavior problem.

History of the Behavior One of the most important pieces of information to gather is the current frequency and intensity of the undesirable behavior. Without this information as a baseline, it will be impossible to determine if a treatment is helping, harming, or having no effect. The speciﬁc circumstances in which the problem behavior is most likely to occur must also be ascertained. In some cases, it may be possible to avoid these situations; in others, the treatment protocol may need to include desensitization and counterconditioning to the speciﬁc circumstances. a

Dr. Crowell-Davis discloses that she has received ﬁnancial support from CEVA Animal Health.

QuickNotes All behaviors that the owner perceives to be problem behaviors need to be identiﬁed.

CompendiumVet.com | January 2009

The history of the behavior is also important. How long has the animal been exhibiting this behavior? While there are exceptions, it is often the case that problems of long duration will take longer to resolve than problems of short duration. This is especially true of behaviors that have developed as a consequence of operant conditioning, such as persistently waking the owners during the night, because the undesirable behavior has been reinforced hundreds or even thousands of times, rather than a few dozen times. Also, in attempts to treat the problem, the owners may have reinforced the undesirable behavior on a variable-ratio or variable-interval schedule by trying to ignore the behavior for a while but eventually acknowledging it. If this is the case, the behavior will have become very resistant to extinction.

History of Treatment Another critical piece of the history is how the owners have already attempted to correct the behavior. There is a tremendous amount of information about animal behavior on the Internet. Some is excellent. Some is mediocre. Some is unclear or confusing, and some will actually make behavior problems worse. Clients are likely to have tried various treatment protocols they have found on the Internet or in books. As with terms describing behaviors, this is a potential area of misunderstanding. Just because a client knows the word desensitization does not mean that the Web site or book where he or she read about it described it accurately or that the client understood the description correctly. Even if the original resource is accurate, the client may have conducted the protocol improperly and attempted a different treatment, such as flooding, instead. Thus, if a client says that he or she has already tried “treatment X,” ask for an exact, detailed description of what he or she did. In some cases, the client has identified the correct behavior modification treatment and conducted it appropriately, and it is helping, but not enough. In this circumstance, confirm that the treatment should be continued. However, it will be necessary to build on the current protocol, perhaps with a new variation of the established behavior modification plan or with medication. In other cases, the treatment may be a reasonable option, and the client may be conducting it accurately, but it is having no effect. In these cases, an entirely different approach is needed. If medications prescribed by other veterinarians have not been effective, verify the medication, the dose, and how long it was given to determine whether it was genuinely not beneficial or was simply not given at an adequate dose for an adequate time. For example, if a client discontinued fluoxetine

after administering it for just 1 week, the medication did not have time to take effect.

Other Behavior Problems The animal may have other behavior problems in addition to the chief complaint. Sometimes these problems come up in the discussion of the chief complaint, but not always. Before proceeding to issues other than the animal’s presenting behavior, ask if the owner has noticed QuickNotes any other behavior problems that have The duration, frenot been mentioned yet. Occasionally, it turns out that the owner considers a quency, intensity, problem other than the presenting com- and context of the plaint to be of more concern but had problem behavnot previously mentioned it because ior need to be he or she believes it to be untreatable. identified. For example, a dog may be aggressive, but the owner has brought it in for storm phobia because of a recent news story about treatments for storm phobia. If the animal has multiple behavior problems, it may be necessary to prioritize treatments. It is rare that the treatments for multiple problems are mutually exclusive. More typically, there are simply limitations to how much time and effort a client can put into treating a pet’s behavior problems. Thus, if a dog has fear aggression toward men, moderate storm phobia, mild separation anxiety, and a nuisance habit of jumping up on women as a form of friendly greeting, and the client can spend approximately 20 minutes a day conducting specific behavior modification, it will be impossible to address all these problems at once. It therefore makes sense to prioritize them in the order presented.

Owner Commitment For some owners, the amount of time and effort necessary to treat one problem, let alone several, is daunting. Therefore, one of the most important pieces of information to obtain at the ﬁrst appointment, in addition to a complete description of any problem behavTO LEARN ior, is a full understanding of how MORE motivated the owner is to treat the problem and keep the pet. At one For more information about end of the spectrum are owners clarifying the correct terms who intend to keep the pet, regardin conversations with less of the success of treatment. At owners, see the December the other end are those who intend 2008 article “Behavior to euthanize or give away the pet Assessment: History Forms if resolution of the behavior proband Interviews” at lem is not quick and easy. If the CompendiumVet.com. owners are considering giving the

CompendiumVet.com | January 2009 | Compendium: Continuing Education for Veterinarians®

Understanding

Behavior pet away, it is important to in which the pet lives. The apprise them of the difficul-same information should Previously attempted treatties of finding an alternative be gathered for all the ments need to be identihome for a pet with a majorr other pets in the household. behavior problem. This is Finally, ask for a complete fied. It is important to especially the case with description of the pet’s physverify that these treatments aggressive pets. Sometimes ical environment, including owners think the police orr the house and yard. How were carried out correctly armed forces will want theirr big is the house? Are there aggressive dog as a guard parts of the house in which and appropriately. The dog. However, for guard and the pet is not allowed? Is the fact that someone knows attack work, police and mili-yard fenced in, and does the tary organizations want onlyy fencing adequately contain a word characteristic of k dogs that are trained to attack the pet? Is the pet walked on the jargon of learning and in a specific way at a spe-a leash? If so, how often and cific command. They do not for how long? What is the behavior modifi cation want dogs that have behaviorr neighborhood like? Is there problems and are likely to a problem with encoundoes not mean that he or infl ict bites because of such tering other pets while on she knows how to conduct issues as fear. walks? Are pedestrians and Beyond the extremes off cars rare, common, or conthe treatment correctly. willingness to keep a pet orr stant? Does this vary with intent to give it up, there is the time of day? the question of how much time and effort an owner Certain aspects of the environment may be idencan and will put into treating a pet. Major behavior tified as contributing to the existence and exacerproblems typically require daily effort by the owner bation of the problem. For example, if the pet is during a period of weeks or months. Even if the nervous and timid, living in the midst of boisterowner is highly motivated to do whatever it takes, ous young children may make improvement difficult it is essential for the owner and the veterinarian to unless a mechanism can be identified to give the pet take a realistic look at the owner’s current schedule time away from the children in a quiet, calm atmoand lifestyle. If the owner can realistically identify sphere. Aspects of the environment that can be used only three times a week in which he or she can to help the pet, or that need to be changed for the do structured behavior modification for 20 minutes, pet, can also be identified. If a healthy young dog it is important to set up a treatment program that is getting inadequate exercise because no one has assumes only three treatment sessions a week. If the time to take it on long walks or jogs, the addition treatment plan assumes that the owner will conduct of fencing in the backyard may be critical. In some behavior modification every day and this is simply cases, the owners may have already been considernot possible, then the owner and the pet are on ing a change (e.g., a fence). The news that making track for failure from the beginning. the change is likely to help their pet may be all that is needed to get them to follow through.

Environment Owner lifestyle is only one aspect of the context in which the pet’s behavior problem exists. To properly identify and treat the problem, it is important to understand all the aspects of the pet’s environment, both social and physical. The social environment includes the people and animals with which the pet regularly interacts. All the humans who either live in the same household as the pet or visit frequently, either as guests or employees (e.g., gardener, maid), need to be identiﬁed. In addition to their names, sexes, and ages, their relationship and interactions with the pet are critical to understanding the world

Signalment Signalment is a basic information set that veterinarians are already accustomed to collecting. As with many medical conditions, signalment often gives us information about the relative likelihood of a given behav-

Compendium: Continuing Education for Veterinarians® | January 2009 | CompendiumVet.com

TO LEARN MORE For more information about cognitive dysfunction, see the February 2008 article “Cognitive Dysfunction in Senior Pets” at CompendiumVet.com.

ior problem. In cases of older pets presenting with behavior problems, it is essential to identify whether the current problem is actually of recent onset. Sometimes owners have tolerated a given behavior problem in a pet for years, but changes in the family circumstances, rather than any substantial changes in the pet, have made the problem less tolerable. If the problem is of recent onset, or if there has been a signiﬁcant change in the intensity or frequency of the problem in an older pet, cognitive dysfunction, analogous to Alzheimer disease, should be considered. However, cognitive dysfunction should not be considered as a possible diagnosis in a young animal. If the complaint is aggression in a dog, aggressively “herding” people or other animals should be a diagnostic differential for herding breeds, but it is unlikely in nonherding breeds. If possible, ﬁnd out about the early history of the pet. Sometimes this is not possible because the owners adopted the pet at several months to several years of age. However, if background information is available, it can be useful in helping the owners understand the problem, even if it does not help

with treatment. Dogs and cats that were born and raised in puppy or kitten mills where they received little to no socialization with humans may be excessively shy around humans and susceptible to developing a variety of anxiety disorders as a consequence of their early experience. QuickNotes Extra effort will be required to help them Signalment will overcome these problems. Likewise, pets that have spent time as strays, fending for assist in prioritizthemselves to survive, may have become ing the differential very aggressive around food, especially diagnosis. if their ability to obtain food while stray was not very successful and they became underweight. Owners who find problem behaviors very frustrating are often more tolerant of them if they understand why their pet behaves in an undesirable fashion.

Conclusion The third article in this series will complete the discussion of the history that needs to be reviewed at the first visit and address direct assessment of the patient.

Clinical Snapshot Particularly intriguing or difﬁcult cases

Case Presentation #1 ❯❯ Karen A. Moriello, DVM, DACVD, University of Wisconsin-Madison A 7-month-old dog presented with “bumps,” a common clinical presentation of superficial bacterial pyoderma in dogs. Note the “goose bumps” or hive-like lesions on the skin. 1. What is the name of this condition, and what is seen upon close examination of the skin? 2. What are the diagnostic differentials, and what diagnostic tests should be conducted to confirm the diagnosis? 3. What is the mechanism of action of fluoroquinolone antibiotics, and why would this drug class not be an appropriate antibiotic choice in this dog?

TO LEARN MORE

Clinical Snapshot presents illustrated case histories and challenges you to answer the questions posed. This case is part of the series of Self-Assessment Colour Review books on multiple topics from Manson Publishing Ltd., London, available from Blackwell Publishing Professional. For more information or to obtain any of the books in the series, call 800-862-6657 or visit BlackwellProfessional.com

SEE PAGE 21 FOR ANSWERS AND EXPLANATIONS.

CompendiumVet.com | January 2009 | Compendium: Continuing Education for Veterinarians®

Behavior

Behavior Assessment: Completing the Examination

About This Column

❯❯ Sharon L. Crowell-Davis, DVM, PhD, DACVB,* The University of Georgia

Behavior problems are a signiﬁcant cause of death (euthanasia) in companion animals. While most veterinary practices are necessarily geared toward the medical aspect of care, there are many opportunities to bring behavior awareness into the clinic for the beneﬁt of the pet, the owner, and ourselves. This column acknowledges the importance of behavior as part of veterinary medicine and speaks practically about using it effectively in daily practice.

The ﬁrst two articles in this series on assessing behavior patients explored the use of history forms and owner interviews to gather information about history, environment, other problems, and owner commitment to treatment. This article addresses direct observation and evaluation of the patient, including interaction with the owner, veterinary staff, and other pets.

Understanding

o understand the relationship between a behavior patient and its owner, comprehensive information about any prior training the patient has received and the degree to which the owner can affect the pet’s behavior through verbal commands is critical. This information is often also important in understanding the development of behavior problems, particularly for dogs. Although most dogs undergo some degree of obedience training, the amount and level of that training can vary widely, from a few sessions conducted by the owner based on tips from a book, DVD, or TV show to many hours of formal training conducted or supervised by a professional. As with many other issues of pet behavior, such as getting “mad,” clear, explicit descriptions are essential to knowing exactly how the animal was trained. If the owners state that positive reinforcement was used, ask exactly what type of positive reinforcement and when. For example, food treats may have been unsuccessful either because they were not sufﬁciently palatable (e.g., dry kibble) or because they were so highly palatable that the pet became extremely excited, resulting in a decreased response to training. Likewise, owners may say that aversive training techniques or punishment were not used because a trainer they consulted told them that leash corrections involving jerking a choke chain against the trachea did not hurt.

QuickNotes

*Dr. Crowell-Davis discloses that she has received ﬁnancial support from CEVA Animal Health.

CompendiumVet.com | February 2009

Detailed, speciﬁc information about the patient’s training history should be obtained.

Sometimes dogs that have been trained using strictly positive reinforcement techniques and are calm during training act very fearful during unstructured interactions with their owners. This is because, in the structured training situation, the owner’s behavior is more predictable and reliable for the dog, whereas during unstructured interactions the dog may be unsure of what the owner is going to do. For a fearful dog, uncertainty about what is going to happen can exacerbate both fear and aggression. If a pet knows how to do a trick on command, the reliability of the interaction during the trick may be useful in treating a variety of behavior problems. For example, one dog with fear aggression that presented to my office only relaxed and exhibited body language indicative of a nonfearful state when family members asked it to “high five” by holding their hand, palm forward, near the dog while saying that phrase. The dog would then raise its paw to touch the hand. All other attempts by family members to initiate interaction with the dog resulted in the dog exhibiting various signs of fear, including laying its ears back against its head, lowering its head and/or tail, growling, and occasionally snapping or biting. During early phases of treatment for the fear aggression, frequent requests to “high five” were used to increase the amount of positive interaction between the dog and the family.

Observing the Patient in the Office Much can be learned by directly observing the patient during the owner interview, while the attention of all the people in the room is superficially directed to each other. For example, cats are typically brought to the clinic in carriers. I usually ask the client to set the carrier on the floor with the door open. Because the veterinarian’s office is a strange and intimidating place, many cats remain in the carrier. Over a period of minutes, some gradually

stick their nose out, then their head, and fi nally exit the carrier very cautiously. A few bolder cats come out more rapidly. Whether and how the cat leaves the carrier is useful information for identifying how timid or bold the animal is. Allowing the cat to leave the security of the carrier when it is ready to also gives it the opportunity to gradually familiarize itself with the room. If two or more cats are presented for QuickNotes fighting at home, observing how they freely interact in the veterinary office In the examination can sometimes be useful; however, it room, some informais usually helpful to obtain the own- tion about the pet’s er’s opinion on the advisability of this temperament can be approach. If the owner believes that gathered by observthe cats fight only under very specific ing its response to circumstances that are unlikely to be its environment, its replicated in the veterinarian’s office, behavior toward its useful information can be obtained by letting the cats out in the office and owners, and its interobserving how they signal each other— actions with clinicians which one stares and which one looks and hospital staff. away; which one walks boldly across the middle of the room and which one hides in a corner or under a chair; which one holds its ears stiffly upright and rotated to the side and which one tucks its ears back against its head. However, if the owner has any concern that the cats might fight in the office, it is best not to let them interact directly. Dogs that are brought in for evaluation should initially be kept on leash and, if there is a history of aggression, in a basket muzzle. If the history does not indicate any background of aggressiveness or excessive fear of strangers, 2 or 3 minutes of observing the dog’s demeanor while on leash in the examination room should be sufficient to verify whether it is safe for the dog to be allowed loose. Allowing the dog to explore the room and people in it is desirable, if it is safe. While the dog is off leash in the examination room, the clinician and staff can develop a rapport with the dog by giving it treats. If the history indicates that TO LEARN the dog should know the correct MORE responses to basic commands (e.g., sit, down), the clinician and staff can test these responses. If a The previous articles in nonaggressive dog has a problem this series, “Behavior Assessment: History Forms with jumping into people’s laps, and Interviews” (December the technique of discouraging this 2008) and “Behavior behavior by repeatedly standing Assessment: The First up and turning one’s back to the Appointment” (January dog can be demonstrated to the 2009) are available at owner. However, some dogs are CompendiumVet.com. so intimidated by strangers or nov-

CompendiumVet.com | February 2009 | Compendium: Continuing Education for Veterinarians®

Understanding

Behavior

elty that they will hide underr ently to specific movements the owner’s chair or refuse or to specific people? Are In cases of extremely fearto leave the owner’s lap. the dog’s reactions consisful or aggressive patients If the history indicates tent with the history? If so, a any degree of aggression, orr stimulus discrimination (e.g., that appear to be physically if the initial behavior of the fear of men, fear of people healthy when observed dog when it enters the exam-wearing hats) may be conination room indicates that firmed. If the reactions are and not touched, and for it might become aggressive,, inconsistent with the history, then the dog should remain the dog’s behavior problem which the owners report restrained on leash by the may be in response to a no physical signs or history owners. Diagnosis can be more general set of stimuli. facilitated by observing the of trauma, subjecting the Observing the Pet at Home dog’s signaling. For example,, patient to a physical examiThe development of inexdoes it prick its ears toward pensive video cameras has the clinician or pin them nation on the fi rst visit may been of great benefit to back against its head? Does the practice of veterinary it hold its tail low or high? cause excessive stress, behavior. Many pet owners Does it show its teeth? If so,, making the physical examiown a video camera (digihow? (Lifting the rostral lips tal or tape) or can borrow off the incisors and canines nation counterproductive. one. While a great deal can may indicate strong self-be learned from interviewconfidence and dominance,, whereas pulling the commissure of the lip caudally ing people who know the patient and observing to expose the premolars and even the molars usu- the patient in the exam room, some behaviors can ally indicates strong fear.) Does the dog react differ- only be fully understood by observing the pet in its regular environment. In some of these cases, a home visit is adequate. However, home visits are often impractical, and in many cases, the pet may not exhibit the undesired behavior when a stranger is in the house. Asking the owner to make a video of the pet’s behavior at home is beneficial in many situations, such as cases of conflict between two or more pets, particularly during specific situations that only occur in the home. Videotaping the pets in this context may provide critical information about their relationship, especially when the owners do not have a good understanding of normal, speciesspecific behavior. For example, two dogs presented to my clinic for fighting. The written descriptions provided by the owner suggested that the dogs were simply engaging in vigorous wrestling play. However, I could not be entirely confident of this diagnosis based only on the owner’s description. Videotaping of a “fighting” incident by the owner confi rmed that the dogs were merely engaging in very loud, boisterous play behavior. Videotapes can also verify and clarify descriptions by owners of pet behavior that is extreme or abnormal, such as a cat repeatedly throwing itself violently against a baby gate in an attempt to attack a cat on the other side of the gate.

Compendium: Continuing Education for Veterinarians® | February 2009 | CompendiumVet.com

Physical Examination Performing a physical examination is, of course, always desirable. However, touching an animal with severe fear of humans can be extremely stressful for the patient. If the owner reports that he or she has not observed any physical signs of illness (e.g., vomiting, diarrhea, coughing, sneezing, runny eyes, lumps) and the patient looks physically healthy, but the patient is likely to have an extreme response to a physical examination, such as violent trembling, struggling, or screaming, the potential to exacerbate the behavior problem by forcefully subjecting the patient to a physical examination should be weighed against the possible beneﬁt of performing the examination. This is also the case with extremely aggressive animals. The stress caused to the patient by subjecting it to the restraints and/or medications that may be necessary to make a physical examination possible and safe for the veterinary staff may outweigh the beneﬁt of the examination. In the extreme cases that are referred to my own clinic, it is not uncommon to delay a physical examination until the second or third visit, QuickNotes when response to the iniIn many cases, it tial treatment makes it posis useful to ask the sible to examine the patient without causing it excessive client to videotape stress or placing anyone in the pet in its home undue danger. environment.

Conclusion Assessing a patient with a major behavior problem is not a quick process. Obtaining a written history provided by people familiar with the patient, directly interviewing people familiar with the patient, watching videotapes of the patient, and directly observing and interacting with the patient in the examination room are all valuable tools for gathering information. The more of these tools that can be used in assessing a patient with a behavior problem, the more likely it is that the problem can be accurately diagnosed and a treatment plan that can be effectively implemented by the family can be developed.

TO LEARN MORE

For more information about how to obtain clinically relevant descriptions from owners, see the December 2008 article “Behavior Assessment: History Forms and Interviews” at CompendiumVet.com.

CompendiumVet.com | February 2009

Understanding

Behavior

Feline Hyperesthesia Syndrome*

About This Column

❯❯ John Ciribassi, DVM, DACVB

Chicagoland Veterinary Behavior Consultants Carol Stream, Illinois

eline hyperesthesia syndrome (FHS) is known by several names, including rolling skin disease, neurodermatitis, neuritis, psychomotor epilepsy, and pruritic dermatitis of Siamese.1,2 As evidenced by these names and by the use of the term syndrome, FHS is not characterized as having a single etiology. In fact, it is often a diagnosis of exclusion. The differential diagnosis for FHS includes diseases related to the ﬁelds of dermatology, neurology, and behavior. Only after conditions relating to skin and the nervous system have been ruled out can this condition be labeled a behavior disorder.

Signalment FHS can occur in cats of any age, but it is commonly seen in cats aged 1 to 5 years. Males and females are equally affected. While all breeds can be affected, Siamese, Burmese, Persian, and Abyssinian cats are more commonly afﬂicted.3

QuickNotes FHS can occur in cats of any age, but it is commonly seen in cats aged 1 to 5 years.

Diagnosis *Adapted with permission from John Ciribassi, DVM, and the Veterinary Information Network (VIN).

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The differential diagnosis for FHS can be categorized by the type of clinical signs displayed:

Clinical Signs As indicated by the name rolling skin disease, affected cats often show rippling or rolling skin along the lumbar spine. Palpation of the lumbar musculature may elicit signs of pain. Mydriasis is common during bouts of FHS. Affected cats commonly stare at their tail, then attack the tail and/or ﬂanks. Biting of the tail base, forelegs, and paws is common. These cats often run wildly around the home, vocalizing at the same time. Normally calm cats may display aggression toward people or other cats in the household, while aggressive cats may display increased affection. The behavior may be induced by petting or stroking the cat’s fur and most commonly occurs in the morning or later in the evening.2

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Understanding

Behavior

QuickNotes Successful therapy is based on reasonable owner expectations and the ability to monitor the degree of improvement.

Dermatologic: Flea allergy dermatitis, food allergy, atopy, infectious dermatitis Neurologic: Epilepsy, brain tumors, spinal disease (disk disease, neoplasia, infectious myelitis) Musculoskeletal: Myositis, myopathy Behavioral: Compulsive disorder, displacement behavior A minimum database to aid in diagnosing FHS should include a physical examination, neurologic examination, complete blood count, serum chemistry profile (especially hepatic and renal function), urinalysis, and spinal radiography. Depending on these results, further diagnostics might include skin scraping, fungal culture, skin and/or muscle biopsy, spinal or cranial imaging (computed tomography or magnetic resonance imaging), electromyography, food trials, and pharmaceutical trials (flea control, corticosteroids, antiseizure medication). The decision of which tests to run and in what order depends on the patience and financial situation of the owner and the severity of the clinical signs. While running the gamut of tests is ideal, it may be more practical to use pharmaceutical trials once the baseline database has been collected. I typically suggest a trial of flea control medication and, if there is no change, treatment with corticosteroids at antiinflammatory doses. If the patient does not respond to steroid treatment, treatment with an antiseizure medication is indicated. Phenobarbital is my initial antiseizure drug of choice; some practitioners also use gabapentin. If none of the above approaches results in an improvement in the cat’s condition, then a presumed diagnosis of behavioral FHS can be made.

Pathophysiology

unrelated, behavior such as grooming. If this conflicting situation persists over a prolonged period, the cat may engage in the displacement behavior even when the competing motivations are no longer present. This is then defined as a compulsive behavior. The environmental factors that trigger compulsive behaviors exert their influence by stimulating the hypothalamus and the limbic system, which in turn activate motor activity through the basal ganglia. Three types of neurotransmitters are reported to be involved: Dopamine. Increased dopamine levels can result in increased frequency of compulsive behaviors. Opiates. One theory is that when animals engage in compulsive behaviors, levels of opiates in the brain are elevated, and the pleasurable effects that opiates promote reinforce the behaviors. Another theory is that opiates initiate stereotypic behavior. This theory is based on the observation that administration of opioids enhances the display of amphetamine-induced stereotypic behaviors, but these behaviors are blocked when narcotic antagonists (such as naloxone) are administered.4 Serotonin. Serotonin is produced in the dorsal raphe nucleus, and its influence on the basal ganglia and frontal cortex affects behaviors such as compulsive disorders. Higher levels of serotonin reduce the incidence of compulsive disorders, which is the rationale for the use of selective serotonin reuptake inhibitors (SSRIs) to treat these disorders.

Treatment Successful therapy is based on reasonable owner expectations and the ability to monitor the degree of improvement. This can be accomplished by recording the frequency and severity of signs of FHS during the treatment period.

FHS is commonly considered to be a compulsive disorder resulting in self-injurious behavior. One proposed trigger of FHS is displacement behavior. Displacement behav- Behavior Modification ior occurs as an alternative to two other con- As with many behavior problems in companflicting behaviors. An example might be a cat ion animals, the treatment of FHS combines that wants to eat but is being prevented from behavior modification protocols and the use doing so by an aggressive cat in the house- of psychoactive pharmaceuticals. Behaviorally, hold. The competing motivations, hunger and the goal is to create a stable and consistent fear, cause the affected cat to want to simulta- environment for the cat. This can be accomneously perform the conflicting behaviors of plished in the following ways: Institute a regular feeding schedule to proeating and escaping. As a consequence, the vide a more predictable source of food. cat might perform a species-appropriate, but

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Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com

Understanding

Behavior

QuickNotes FHS behaviors should not be punished because punishment will increase the cat’s conﬂict and stress, resulting in a likely increase in the problem behaviors.

CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians®

Maintain consistency in interactions with the administration of the medication. If the patient cat. When managing dogs with a compulsive is receiving combination therapy (an SSRI or disorder, one common recommendation is TCA with a benzodiazepine), the medications for the owners to use a command–response– should be weaned one at a time to determine reward technique for all interactions. For which drug is responsible if signs return as the example, the owner asks the dog to sit and, dose is reduced. after the dog obeys, gives it a treat. The same Selective Serotonin Reuptake Inhibitors technique can be used with cats. Provide regular play sessions using target- The following dosages are recommended for type toys (e.g., feather toys). cats with FHS6: Anticipate situations that trigger the behavior. Fluoxetine: 0.5 to 2.0 mg/kg PO q24h When the behavior is likely to occur, redirect Paroxetine: 0.5 to 1.0 mg/kg PO q12–24h the cat’s activity to more appropriate behaviors, such as training exercises or play.3,5 The adverse effects of SSRIs include sedaFHS behaviors should not be punished tion, anorexia, irritability, vomiting, and diarbecause punishment will increase the cat’s con- rhea. In addition, SSRIs inhibit the function of flict and stress, resulting in a likely increase in the liver cytochrome P450 enzymes CYP2C9, the problem behaviors. CYP2D6, CYP2C19, and CYP3A4. As a consequence, care should be taken when prescribPharmaceutical Intervention ing concurrent medications that rely on these There are no US Food and Drug Administration– enzymes for their metabolism (e.g., phenoapproved medications for treating FHS or barbital, carbamazepine, benzodiazepines, any other compulsive disorder in pets. Con- TCAs). SSRIs should not be used in combinasequently, owners should be informed of the tion with each other or with other drugs that potential risks as well as the possible benefits increase serotonin levels, such as monoamof the use of behavior medications. It is always ine oxidase inhibitors (e.g., selegiline), other wise to conduct appropriate laboratory testing SSRIs (e.g., paroxetine, sertraline), or TCAs to confirm normal hepatic and renal function (e.g., amitriptyline, imipramine, doxepin). before prescribing these medications, which are metabolized and eliminated by the liver Tricyclic Antidepressants and kidneys. It is also helpful to repeat test- Of the TCAs, clomipramine (0.5 to 1.0 mg/kg ing approximately 4 weeks after instituting PO q24h)7 can be used to treat FHS. Adverse therapy to evaluate the medication’s effect on effects associated with this drug include sedation, anticholinergic effects, potentiation organ (particularly hepatic) function. The three main classes of medications used of arrhythmias in predisposed patients, and to treat FHS are SSRIs, tricyclic antidepressants lowering of the seizure threshold in patients (TCAs), and benzodiazepines. When using any with seizure disorders. of these medications in cats, it is best to begin at the lower end of the dose range, then titrate Benzodiazepines upward as needed to achieve the desired The following dosages 8 are recomresponse. This approach minimizes the poten- mended for cats with FHS. These tial for serious side effects such as prolonged benzodiazepines are recommended in cats because they do not have active anorexia or excessive sedation. Once the frequency of the behavior metabolites. Diazepam has been implireaches an acceptable level, treatment should cated in cases of hepatic necrosis in cats. Lorazepam: 0.125 to 0.50 mg PO q8–24h be maintained for 4 to 6 months. The dose Oxazepam: 0.20 to 0.50 mg/kg PO q12–24h can then be gradually reduced (25% reduction every 1 to 2 weeks) until the patient has been weaned off the drug. If the behavior recurs The potential adverse effects of these drugs or increases in frequency during the weaning include sedation, ataxia, and temperament process, the previously effective dose should changes. Combination therapy with an SSRI or be reinstituted. Another reduction may be a TCA is acceptable with either of these drugs attempted after another 4 to 6 months of ther- if no agent alone provides sufficient response. CONTINUES ON PAGE 132 apy; however, some patients require lifelong

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Reading Room*

his book offers the veterinary health care team a pragmatic approach to behavior and training issues in puppies and kittens—in the author’s words, addressing “behavioral needs before they become behavior problems.” It does not cover behavior theories but rather draws on the author’s 30 years of training experience to offer practical advice and methods for achieving cooperation and harmony between owner and pet.

This practical book will help veterinarians realize the goal of a full-service practice that addresses every aspect of pet health and well-being. Title: First Steps With Puppies and Kittens: A Practice-Team Approach to Behavior Author: Linda M. White Publisher: American Animal Hospital Association Press Year: 2008 Pages: 211 ISBN: 978-1-58326-101-9

TO LEARN MORE For further information about this book or to order a copy, visit aahanet.org.

426

Because they know that they are the primary source of advice concerning all aspects of pet ownership, most veterinarians provide information about feeding, care, and training during the initial puppy or kitten visit. Unfortunately, owners frequently feel overwhelmed, retaining only a portion of the instructions, and many practices are too busy to implement a comprehensive, ongoing training program. This book explains how such a program can be developed. It takes the reader step by step through the process and describes how to involve every member of the health care team in the effort. It also comes with a companion CD containing forms and instructional materials that can be customized and printed out to give to owners. The book begins with a discussion of the “business side” of training, addressing ﬁnancial considerations and the roles of various members of the health care team. The author describes how the veterinary team can become “patient behavior advocates” using methods such as operant and associative conditioning and verbal, target, and clicker training. Concepts include reinforcement and punishment, extinction, cure, reward, shaping, and counterconditioning. Special emphasis is given to socialization and desensitization. This is followed by a detailed section on puppy development that

Compendium: Continuing Education for Veterinarians® | September 2009 | CompendiumVet.com

covers basic commands (e.g., come, down, sit, stay) and how to handle undesirable behaviors such as barking, biting, and “counter surfing.” The next chapter similarly covers kitten development and behavior, including common problems like scratching, biting, and litterbox issues. These chapters, which establish the fundamentals of the training program, are followed by six appendixes with samples of handouts dealing with every issue raised in the book. The material is presented in brief, discrete sections, highlighted by a wealth of useful lists. Each training exercise is broken down into specific, detailed steps tailored to the particular behavior in question. Equipment is described as well, including collars, leashes, harnesses, and training aids. This practical book will help veterinarians realize the goal of a fullservice practice that addresses every aspect of pet health and well-being. By viewing the pet and owner-family as a whole, rather than individuals, it should help veterinarians promote the human–animal bond to enable owners to work with their pets in the animals’ best interests, as well as help establish behaviors that will lead to less stressful office visits and more practice loyalty. *Written by Patricia L. Van Horn, a freelance writer in Long Branch, New Jersey.

Understanding

Generalized Anxiety Disorder ❯❯ Sharon L. Crowell-Davis, DVM, PhD, DACVBa The University of Georgia

hobias in pets are commonly assumed to be associated with speciﬁc stimuli, such as thunderstorms, loud noises, strangers, separation from an owner, or the outdoors. However, some dogs and cats chronically exhibit signs of anxiety regardless of their situation. While demonstrations of fear may intensify when these animals are exposed to certain situations or stimuli, such pets are rarely or never truly relaxed and calm. These pets may have generalized anxiety disorder (GAD).

Clinical Signs In humans, the essential feature of GAD is defined as follows: …excessive anxiety and worry (apprehensive expectation), occurring more days than not for a period of at least 6 months, about a number of events or activities […] the intensity, duration, or frequency of the anxiety and worry is far out of proportion to the actual likelihood or impact of the feared event.1 People with GAD have difficulty controlling their almost constant worrying and report a variety of symptoms, including restlessness, being easily fatigued, difficulty concentrating, irritability, muscle tension, disturbed sleep, cold or clammy hands, dry mouth, sweating, nausea or diarrhea, frequent urination, and trouble swallowing. The exact way in which GAD manifests varies depending on the affected individual’s culture. Regardless of culture, however, the anxiety, worry, and physical symptoms are significant enough to interfere with a person’s ability to function normally in a social, occupational, or other important context. Animal patients sometimes exhibit signs that are analogous to symptoms of GAD in humans. Specifically, the animal shows constant or almost constant signs of fear and anxiety, regardless of the situation it is in or the stimuli to which it is exposed. Specific behaviors, such as those listed in BOX 1, vary depending on the patient.

Behavior About This Series Behavior problems are a signiﬁcant cause of death (euthanasia) in companion animals. While most veterinary practices are necessarily geared toward the medical aspect of care, there are many opportunities to bring behavior awareness into the clinic for the beneﬁt of the pet, the owner, and ourselves. This series acknowledges the importance of behavior as part of veterinary medicine and speaks practically about using it effectively in daily practice. SERIES EDITOR Sharon L. CrowellDavis, DVM, PhD, DACVB The University of Georgia

QuickNotes Pets with generalized anxiety disorder exhibit behaviors indicative of mild to severe anxiety most or all of the time and in a wide variety of contexts.

History and Diagnosis Pets with GAD may present to the veterinary clinic for an apparent speciﬁc fear-related disorder

a Dr. Crowell-Davis discloses that she has received ﬁnancial support from CEVA Animal Health.

CompendiumVet.com

427

Understanding

Behavior

QuickNotes Pets with generalized anxiety disorder may also have speciﬁc phobias.

(e.g., separation anxiety, storm phobia, fear aggression, subSigns of Anxiety missive urination) beTrembling cause their fear—and consequent problem Persistent vocalizing behaviors—becomes Urinating more common or Defecating more intense in cerSalivating tain situations. For Pacing example, the owners of a dog with GAD Panting even when not in a hot environment may state that the dog trembles and Hiding hides under the furPersistently holding niture during storms. the ears back against If the dog’s behavior the neck in the examination Persistently holding room is also indicathe mouth in a tive of anxiety, it is submissive grin important to ask how Destructiveness the dog acts in other Freezing (not moving) situations. If the dog’s fear is context specific, the owners will describe the dog as “happy” or “relaxed” in other contexts (e.g., good weather, at home). However, it is also important to ask about specific somatic signals, such as pinning the ears against the neck or holding the lips in a submissive grin. Some owners are not sufficiently familiar with canine communication to understand that if their dog is thumping its tail while displaying a submissive grin and pinning its ears back, it is displaying some degree of arousal coupled with anxiety, not happiness. The owners should describe the pet’s BOX 1

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specific signals in a variety of situations, especially when the pet is in its own home, the owners are present, and nothing obvious is happening to disturb the pet. If the pet is almost constantly demonstrating signals of fear and anxiety, regardless of context, and simply gets worse in particular situations, then the pet has GAD. In contrast, some owners may present their pet because they have already perceived a more general problem. They may describe the pet as seeming consistently “miserable” or “frightened.” These pets may not demonstrate exacerbated signs of fear in specific contexts. Instead, they simply exhibit low levels of behavior indicative of anxiety most of the time. The owners may make comments like, “He’s never happy.” As for pets that present because of exacerbation of specific behaviors in specific situations, it is important to ask for detailed descriptions of behaviors that cause the owner to believe the pet is unhappy, anxious, miserable, or frightened. Animals that have had prior stressful experiences (e.g., abuse, repeated homelessness) commonly display some degree of chronic, low-level anxiety when they are taken into a new home. As these animals persistently experience a loving, stable environment over a period of days or weeks, many show decreased signs of anxiety. However, if the passage of 2 to 3 months does not improve the pet’s general level of anxiety, GAD should be presumed and the pet treated accordingly.

Treatment Once a pet has been identiﬁed as being chronically anxious, medication is a critical component of treatment. A selective serotonin reuptake inhibi-

Compendium: Continuing Education for Veterinarians® | September 2009 | CompendiumVet.com

Understanding

Behavior TABLE 1

Medications That May Beneﬁt Pets With Generalized Anxiety Disordera–c Medication

Dogs

Cats

Fluoxetine

1–2 mg/kg q24h

0.5–1.5 mg/kg q24h

Paroxetine

1–1.5 mg/kg q24h

0.5–1.5 mg/kg q24h

Sertraline

0.5–4.0 mg/kg q24h

0.5–1.5 mg/kg q24h

Clomipramine

1–3 mg/kg q12h

0.24–1.3 mg/kg q24h

Buspirone

0.5–2.0 mg/kg q8–24h

0.5–1.0 mg/kg q12h

aCrowell-Davis SL, Murray T. Selective serotonin reuptake inhibitors. In: Veterinary Psychopharmacology. Ames, Iowa: Blackwell Publish-

ing; 2006:80-100. bCrowell-Davis SL, Murray T. Tricyclic antidepressants. Veterinary Psychopharmacology. Ames, Iowa: Blackwell Publishing; 2006:179-206. cCrowell-Davis SL, Murray T. Azapirones. Veterinary Psychopharmacology. Ames, Iowa: Blackwell Publishing; 2006:111-118.

tor, serotonin and norepinephrine reuptake inhibi- it engages in a desired behavior), should never be tor, or azapirone can beneﬁt most cases (TABLE 1). used when handling pets with GAD. These trainThese drugs are given daily over a period of weeks ing techniques include such common practices as to effect a long-term change in the pet’s underly- “leash correction,” in which, if the pet does not obey ing emotional state. Because of their potential for a command, the leash is jerked, snapping the coladdiction and the chronic nature of GAD, benzodi- lar against the skin covering the trachea, external azepines are not good choices for the primary treat- jugular vein, carotid artery, and vagoment of this disorder. However, if the pet shows an sympathetic nerve trunk, until the QuickNotes exacerbation of fear in particular contexts, benzo- pet does obey the command. Instead, Effective treatdiazepines can be useful supplements, especially if desired behaviors should be encourment requires the they can be given 30 to 60 minutes before an exac- aged and reinforced, and the owners erbating situation (TABLE 2). should attempt to prevent undesired use of appropriate Along with medication, all training protocols behaviors by logical management. medication. should be reviewed to identify and minimize stres- For example, if the pet chews on cersors in the pet’s life. Training techniques that involve tain objects (e.g., electronic remote control devices), aversive stimuli, such as positive punishment (an these objects should be kept out of the pet’s reach. aversive stimulus occurs when the pet engages in Otherwise, undesirable behaviors should be ignored an undesired behavior) and negative reinforcement because use of aversive stimuli will only worsen the (the pet experiences an aversive stimulus unless pet’s anxiety and potentially exacerbate the severity TABLE 2

Benzodiazepines Commonly Used in Dogs and Catsa,b Generic name

Dogs

Cats

Alprazolam

0.02–0.1 mg/kg q4h

0.0125–0.25 mg/kg q8h

Chlordiazepoxide

2.0–6.5 mg/kg q8h

0.2–1.0 mg/kg q12h

Clonazepam

0.1–0.5 mg/kg q8h

0.015–0.2 mg/kg q8h

Clorazepate dipotassium

0.5–2.0 mg/kg q4h

0.5–2.0 mg/kg q12h

Diazepam

0.5–2.0 mg/kg q4h

0.1–1.0 mg/kg q4h

Flurazepam

0.1–0.5 mg/kg q12h

0.1–0.4 mg/kg q12h

Lorazepam

0.02–0.5 mg/kg q8h

0.03–0.08 mg/kg q12h

Oxazepam

0.04–0.5 mg/kg q6h

0.2–1.0 mg/kg q12h

aCrowell-Davis SL, Murray T. Benzodiazepines. In: Veterinary Psychopharmacology. Ames, Iowa: Blackwell Publishing; 2006:34-71. bThe dose frequency is the maximum frequency that should be used. The lowest dose and frequency that alleviate the fear should be used.

CompendiumVet.com | September 2009 | Compendium: Continuing Education for Veterinarians®

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Understanding

Behavior

QuickNotes

of the clinical signs or cause the manifestation of new signs. A safe, predictable As much as possible, a stable, preenvironment with reg- dictable environment should be provided for the pet. This does not mean ular pleasant experithat the family must stick to a rigorences is required ous and specific schedule, but there for improvement. should be enough consistency in the Recovery is likely pet’s day that it can learn which events to require weeks to predict certain subsequent events and months of treatment. can expect things to happen in a certain order. Efforts by the family to elicit relaxation, play, or other “happy” behaviors can be beneficial. The most effective stimulus varies from patient to patient. Some pets respond well to delicious food treats; others are relatively uninterested in food. In severe cases, the pet may have a poor appetite due to chronic anxiety, and the use of appetite-stimulating benzodiazepines may be beneficial for the fi rst weeks of treatment. Other pets respond better to gentle petting or massage from someone they are familiar with, while others may exhibit their rare moments of “happiness” (e.g., relaxed face, ears up) when a Frisbee is thrown. Many other solutions exist, and it is important to communicate with the family about identifying and extending the situations in which their pet does seem to be relaxed or happy. Various products that provide environmental enrichment can also be useful. Regardless of the specific treatment, the owners should watch for signals of relaxation,

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alertness, and playfulness and facilitate the repetition of those signals. It is important for the family to understand the need for patience. Whether the pet has developed GAD because of genetic factors that make it overreactive to fear-inducing stimuli; a single, severe traumatic event; chronic environmental deprivation at a young age; repeated exposure to fear-inducing stimuli; or some other cause, recovery is likely to require weeks or months. Family members should endeavor to be relaxed when around their anxious pet and should not engage in excessive consoling behavior. While emotions such as fear cannot be operantly reinforced, some behaviors that are common indicators of fear can be. Thus, if a dog learns that leaning against a person’s legs and whining results in its being picked up, cuddled, talked to in a soft voice, and fed treats, it will become more likely to engage in that behavior.

Conclusion The major criterion for identifying a pet as having GAD is the persistence and frequency of behaviors indicative of anxiety, even low levels of anxiety, over long periods of time. The standard criterion in human psychiatric medicine is 6 months. In the case of adopted pets whose earlier history is not known, GAD should be assumed if chronic anxiety persists 2 to 3 months after the pet has been provided with a stable, loving, secure household free of aversive stimuli. Reference 1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 1994.

Compendium: Continuing Education for Veterinarians® | September 2009 | CompendiumVet.com

Letters AAFP Retrovirus Guidelines I read the recent Feline Focus article (June 2009) on FeLV/FIV testing and vaccination guidelines and wanted to make a brief comment about the FIV vaccine. As the article implies, vaccination with the FIV vaccine interferes with the ability to test cats for FIV infection because vaccinated cats will have positive FIV test results. Our clinic recently referred a cat to a university hospital for kidney transplant consultation. The cat was declined because it had received the FIV vaccine and therefore tested positive for FIV. Although the university knew we had vaccinated this cat, the pet was not a candidate for kidney transplantation because immunosuppressive drugs would be used to regulate organ rejection, and if the cat was truly infected, these drugs would cause a detrimental outcome. The university’s rationale was that, at present, there is no reliable test to differentiate vaccinated from naturally infected cats. Therefore, another important, if uncommon, criterion that veterinarians need to assess before administering the FIV vaccine is whether their client would pursue kidney transplantation if their cat developed kidney disease in the future. Marguerite Hoey, DVM Kearny, New Jersey

The Editor’s Reply Thank you very much for sharing your experience. Most veterinarians would not readily think of this repercussion given that recommendations for renal transplantation are still relatively uncommon. However, it is a very real concern because of the inability to distinguish between antibodies induced by vaccination and those induced by infection.1 It is also theoretically possible for a cat to possess wild-type and vaccination antibodies from having been both infected and vaccinated because we do not conclusively know the full spectrum of serovar (serotype/strain/clade) protection afforded by the existing vaccine. Five subtypes, or clades, of FIV have been characterized and are classiﬁed by

the letters A through E. Other subtypes may exist in nature. The most common FIV subtypes in North America are A, B, and C. The current FIV vaccine contains a mix of subtype A (Petaluma strain) and subtype D (Shizuoka strain) virus. The challenge virus used in the licensing study was a subtype A virus (strain not identiﬁed). Two subsequent studies evaluated protection against infection with two different subtype B strains. In one, 100% protection was noted2; in the other, less than 100% protection was achieved.3 Another study using a subtype A strain was not protective, and 100% of the cats, both control and vaccinated, became infected when challenged.4 Many thanks for bringing this concern regarding vaccination and lack of

2008 Feline Retrovirus Management Guidelines* Members of the Advisory Panel gg Julie Levy, DVM, PhD, DACVIM, Chair gg Cynda Crawford, DVM, PhD University of Florida

gg Katrin Hartmann, Dr. Med. Vet., Dr. Habil., DECVIN-CA Ludwig Maximilian University Munich | Munich, Germany

A cat with a conﬁrmed-positive test result should be diagnosed as having a retroviral infection—not clinical disease. Diseases in cats infected with FeLV or FIV may not necessarily be the result of the retrovirus infection. Cats infected with FeLV or FIV may live for many years. A decision for euthanasia should never be made solely on the basis of whether the cat is infected. No test is 100% accurate at all times under all conditions. All test results should be interpreted along with the patient’s health and prior likelihood of infection. All positive results should be conﬁrmed by another test method.

gg Regina Hoffmann-Lehmann, Dr. Med. Vet., Dr. Habil, FVH University of Zurich | Zurich, Switzerland

gg Susan Little, DVM, DABVP (Feline Practice) Winn Feline Foundation | Manasquan, New Jersey

gg Eliza Sundahl, DVM, DABVP (Feline Practice)

While FeLV and FIV can be life-threatening viruses, proper management can give infected cats longer, healthier lives. The following article reﬂects the recommendations of the AAFP on managing these infections.

KC Cat Clinic | Kansas City, Missouri

gg Vicki Thayer, DVM, DABVP (Feline Practice) Purrfect Practice | Lebanon, Oregon

At a Glance Epidemiology Page 265

Preventing FeLV and FIV Infection Page 265

Limiting Transmission in the Veterinary Practice Page 268

Diagnosing FeLV and FIV Page 269

About These Guidelines This report represents a consensus of current information compiled by the researchers and practitioners on the panel. These guidelines are based on the best research data, clinical experience and technical judgments available at the time of preparation. While the guidelines are as accurate and comprehensive as possible, they are subject to change should new insights become available from additional research or technological updates. The American Association of Feline Practitioners is a professional organization of practitioners and board-certiﬁed specialists who seek to raise the standards of feline medicine and surgery among practitioners.

Managing Positive Cats Page 270

*This is an abridged version of the full guidelines (Levy JC, Crawford C, Hartmann K, et al. 2008 American Association of Feline Practitioners’ feline retrovirus management guidelines. J Feline Med Surg 2008;10[3]:300-316) available at catvets.com from the American Association of Feline Practitioners (AAFP). Adapted with permission from AAFP.

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