The Modern Equine Vet November 2015 by The Modern Equine Vet

The Modern

Equine Vet www.modernequinevet.com

Vol 5 Issue 11 2015

Diagnosing Colic Putting together the jigsaw puzzle

New Lepto vaccine NEAEP Meeting: Field strategies for treating colitis Incorporating acupuncture into your practice 5 tips for the Vet Tech

Table of Contents

Cover story:

Diagnosis of colic: 6 Putting together the jigsaw puzzle Cover photo courtesy of Southward

Gastrointestinal disease

Field strategies for treating colic......................................................................................11 HOlistic Medicine

Integrating acupuncture into the veterinary treatment of horses.............................................................................14 technician update

5 tips for the large animal hospital............................................19 News

Zoetis introduces first equine leptospirosis vaccine................................................3 Tourniquet for IR-RLP increases joint drug concentrations?.....................................................................................................................17 advertisers Diagnostic Imaging Systems..................................... 3 Merck Animal Health.................................................. 4

Universal Imaging....................................................... 7 AAEVT............................................................................20

The Modern

Equine Vet Sales: Matthew Todd • ModernEquineVet@gmail.com Editor: Marie Rosenthal • mrosenthal@percybo.com Art Director: Jennifer Barlow • jbarlow@percybo.com contributing writerS: Paul Basillo • Kathleen Ogle COPY EDITOR: Patty Wall Published by PO Box 935 • Morrisville, PA 19067 Marie Rosenthal and Jennifer Barlow, Publishers percybo media  publishing

Issue 11/2015 | ModernEquineVet.com

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news notes

Zoetis Introduces First Equine Leptospirosis Vaccine The Department of Agriculture recently approved Lepto EQ Innovator (Zoetis), the first vaccine indicated for the prevention of leptospirosis caused by Leptospira interrogans serovar Pomona, known as L. pomona. A recent study supported by Zoetis showed 75% of healthy horses have been exposed to at least one leptospiral serovar. As clinical signs associated with leptospirosis are non-specific, disease in horses likely occurs more frequently than is diagnosed, and exposure to Leptospira may be more prevalent than was previously understood, the company said.

Leptospira-infected urine, contaminated soil, bedding, feed and drinking water as well as urine from infected cattle or dogs. Common maintenance hosts, including skunks, raccoons, white-tailed deer and opossums, can become infected with L. pomona, which can be shed into shared environments and infect horses. After penetrating through mucous membranes or skin abrasions, leptospires can concentrate in the kidneys and can cause devastating clinical disease. For more information contact your Zoetis representative or visit www.LEPTOEQUINNOVATOR. COM to access a free, online Leptospirosis Risk Assessment. For each completed risk assessment, Zoetis will donate $1.00 USD, up to $1,000, to A Home for Every Horse, an organization that works with rescue horses to connect them with loving homes. Lepto EQ Innovator is currently available.

Regional seroprevalence of leptospirosis. Courtesy of Zoetis.

“Until this vaccine, preventive options against leptospirosis have been limited in horses,” said Jacquelin Boggs, DVM, MS, ACVIM, senior veterinarian, Equine Technical Services at Zoetis. “Leptospirosis is a disease that can cause devastating health risks to horses and can require costly treatment.” Lepto EQ Innovator was shown to be clinically safe for use in foals 3 months of age or older and healthy pregnant mares in the second trimester. The vaccine has been field tested in more than 1,800 horses. In field safety studies with the administration of 1,808 vaccine doses, 99.8% of the horses remained reaction-free. The vaccine is indicated for use in horses 6 months of age or older. Equine leptospirosis is an infectious bacterial disease caused by spirochetes belonging to Leptospira species. L. pomona is the serovar most often associated with leptospirosis infections in horses in North America. The organism can colonize in the kidneys, be shed in the urine and cause horses to become septicemic. The bacteria are circulated in the blood and can cause uveitis, or moon blindness (the most common cause of blindness in horses), as well as abortions and kidney failure. Horses can become infected with leptospires from standing or slow-moving water contaminated by

800-346-9729

BIT.LY/DRWIZARD ModernEquineVet.com | Issue 11/2015

Some dewormers claim just one dose of their product is the best way to deworm your horse, but that’s simply not true. Demand Safety: You won’t find a laundry list of warnings and precautions on the PANACUR® (fenbendazole) POWERPAC label, like those other dewormers, because fenbendazole has a unique mode of action that makes it safe for horses of all ages, sizes and body conditions.

Demand Efficacy: PANACUR POWERPAC is the only dewormer FDA approved to treat ALL STAGES of the encysted small strongyle.1 Other dewormers miss a critical stage, EL3, which can account for up to 75% of the encysted small strongyle burden. Plus, it’s the best choice for treating ascarids – which are not just a problem in young horses!

SO WHEN IT COMES TO WHICH DEWORMER TO TRUST, DON’T FORGET THERE’S SAFETY IN NUMBERS. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism. Do not use in horses intended for human consumption. When using Panacur® (fenbendazole) Paste 10% concomitantly with trichlorfon, refer to the manufacturers labels for use and cautions for trichlorfon. PANACUR (fenbendazole) POWERPAC Equine Dewormer product label. © 2015 Intervet Inc., d/b/a Merck Animal Health, a subsidiary of Merck & Co., Inc. All rights reserved.

ADVE RTO R IAL

DEWORMING IN FIVE DOSES – THE FACTS When it comes to dewormers, only one unique and popular product can be distinguished from all others for one very important reason: A five-dose regimen. This five-day regimen results in one of the safest, most comprehensive and effective methods to treat a wide variety of parasites in a wide variety of horses. This regimen is known as the PANACUR® (fenbendazole) POWERPAC and is a larvicidal dose of fenbendazole.

FACT IS 5 IS GREATER THAN 1

FACT: PANACUR POWERPAC IS EXTREMELY SAFE.

Safety is the most important feature of any pharmaceutical product. If you’re not already, you should be reviewing the warning label on dewormers. You’d be surprised at the amount of warnings that come with some equine dewormers, including ivermectin and moxidectin products. In big bold print, you’ll see phrases such as “Extreme caution should be used when administering the product to foals, young and miniature horses…Do not use in sick, debilitated or underweight animals.” And “This product should not be used in other animal species as severe adverse reactions, including fatalities in dogs, may result.” Fenbendazole has an exceptional safety profile and is safe for every horse on your farm, regardless of their age, size or body condition. It is safe for the environment as well as in non-target species, and there are no known contraindications. Due to its gentle mode of action, fenbendazole may help decrease the likelihood of potential side effects, such as endotoxic shock and impactions, which may occur after deworming foals with heavy roundworm infections using other classes of dewormers. i Fenbendazole has demonstrated a wide margin of safety in well-controlled safety studies in horses with single doses as high as 1000 mg/kg (that’s 200 times the label dose), and for 15 consecutive daily doses at 50 mg/kg. ii

FACT: PANACUR POWERPAC IS THE BEST CHOICE FOR ASCARID PROTECTION.

PANACUR POWERPAC is widely recognized as the best product for treating ascarids, one of the most significant and potentially life threatening parasites in young horses, and a growing problem in adult horses. This is because: • There are a growing number of reports of ascarids resistant to macrocyclic lactones and pyrantel pamoate. Larvicidal doses of fenbendazole have been proven to be efficacious against ivermectin-resistant ascarids. iv • Its safety. Its mode of action results in a slow kill of parasites. The other anthelmintic classes approved for use in foals (pyrantel salts and macrocyclic lactones – e.g., ivermectin) affect the nervous system of worms, which kills them quickly. The latter situation seems to result in small intestinal impactions with dead ascarids more frequently than after treatment with fenbendazole. i, v • Due to widespread resistance to ivermectin and moxidectin, ascarids can also threaten horses beyond the age of 18 months if these animals were not effectively dewormed as foals and have harbored an ascarid infection into adulthood.

FACT: THE FIVE-DOSE PANACUR POWERPAC REGIMEN IS GREATER THAN ANY ONE DOSE OF OTHER DEWORMERS.

It’s more than math. It’s science. When used as part of a veterinarian-guided, strategic deworming program, the five-dose PANACUR POWERPAC deworming regimen shows unmatched efficacy and safety against a wide variety of parasites in a wide variety of horses. Remember, deworming is only one part of the solution to parasite control. Sound husbandry practices will improve the efficacy of any deworming program, which is yet another reason to work with your veterinarian. Dewormers such as PANACUR POWERPAC have the best chance of success when partnered with fecal monitoring and strategic use of non-chemical parasite control strategies. Get the facts and incorporate PANACUR POWERPAC into your deworming strategy for a healthier horse inside and out.

FACT: PANACUR POWERPAC WORKS ON A WIDE VARIETY OF PARASITES.

PANACUR POWERPAC (fenbendazole 10 mg/kg daily for 5 days) treats a majority of the most common internal parasites affecting horses. It is labeled for the control of large and small strongyles (including migrating larvae), pinworms and ascarids (roundworms). Additionally, it is the only U.S. Food and Drug Administration (FDA) approved treatment labeled for all stages of encysted small strongyles, including early third stage larvae (EL3), which can account for up to 75 percent of the encysted small strongyle burden.

FACT: PANACUR POWERPAC WORKS IN A WIDE VARIETY OF HORSES.

Young and old and everything in between. Not only is PANACUR POWERPAC considered the best treatment option for ascarids in foals, but the larvicidal dose is often recommended every year for: • Moderate-to-high strongyle egg shedders • Incoming horses before co-mingling with resident horses • Before starting on a daily dewormer, and once a year while continuing a daily deworming program • Prior to a performance event for show horses • The treatment of debilitated or thin horses suffering from internal parasites, horses with chronic diarrhea, recurring colic and chronic weight loss due to suspected parasite infection. iii

Do not use in horses intended for human consumption. Consult your veterinarian for assistance in the diagnosis, treatment and control of parasitism. i

AAEP Parasite Control Guidelines. Revised 2013.

PANACUR (fenbendazole) POWERPAC Equine Dewormer product label. iii Tamzali Y. (2006) Chronic weight loss in the horse: a 60 case retrospective study. Equine Vet Edu. 18, 289-296. ii

Reinemeyer CR, Vaala, WE. Larvicidal efficacy of fenbendazole against a macrocyclic lactone-resistant isolate of Parascaris equorum in foals. 2010 AAEP Proceedings.

Cribb, NC, Cote, NM, Bouré, LP, Peregrine, AS. Acute small intestinal obstruction associated with Parascaris equorum infection in young horses: 25 cases (1985-2004). N Z Vet J. 2006 Dec;54(6):338-43.

cover story

Diagnosis of colic:

Putting together the jigsaw puzzle Faster referral for a colicky horse improves outcomes B y 6

M a r i e

Issue 11/2015 | ModernEquineVet.com

R o s e n t h a l ,

M S

Photo courtesy of Southward

A colic case is a jigsaw

puzzle filled with pieces that provide a coherent picture, but it is important to collect the pieces quickly. The faster that a serious colic case is referred for surgery, the better the horse's chances for recovery, according to several experts who spoke at the 2015 British Equine Veterinarian Association (BEVA) Congress. â&#x20AC;&#x153;When we are called to examine colic in the field, our initial assessment is to decide whether we are dealing with a benign disease that may improve spontaneously or may improve with medical treatment or serious disease, where we need to consider referral,â&#x20AC;? said Timothy Mair, MRCVS, PhD, DEIM, DESTS, DECEIM, Bell Equine Veterinary Clinic in

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C0ver story

Normal Peritoneal Fluid Parameters • Color: Clear to yellow ** • Specific gravity: 1.005 mg/dL • Total nucleated cell count: <10 x 109 L • Total protein: <25 g/L ** • Lactate: <1 mmol/L and should be less than blood lactate concentration ** ** Measurements that can be made stall side.

Kent, United Kingdom. “But we need to make this decision early on, so that the owner and referring vet can make informed decisions.” The field veterinarian must suggest the best treatment options, discuss the risks and complications, think about cost implications, and then institute appropriate therapy that is specific for that individual circumstance, according to Dr. Mair. It is less important to determine a precise reason for the colic, rather to establish how painful the horse is and whether it would

benefit from a hospital stay, said Louise Southward, BVSc, PhD, DACVS, DACVECC, Associate Professor of Emergency Medicine and Critical Care (CE), University of Pennsylvania School of Veterinary Medicine in Pennsylvania. Although she would rather see a horse that can be treated medically because the outcomes are typically better, medical management is not suitable for all cases. If surgery is required, time is of the essence. “I think the important thing we need to keep in mind when we are looking at these patients is whether the horse is likely to respond to medical management or does it need to go to surgery. We don’t necessarily need to obtain a definitive diagnosis in every case,” Dr. Southward explained. Diagnosing colic in the field is a challenge, but there are some good general assessments that will help the field veterinarian make that call. Even some horses that can be managed medically might still be better off in the hospital, according to Debra Archer, BVMS, PhD, CertES (Soft Tissue), DipECVS, MRCVS, Head of Equine Surgery and Professor at the University of Liverpool. “I don’t think we should beat

ourselves up if we don’t come up with a precise diagnosis. Even with all the gadgets that we have [in the hospital], it still amazes me what we find when we surgically go into the abdomen,” Prof. Archer said. “The key thing in diagnosis is: Do I think something surgical is going on? If surgery is not an option, do I think ‘euthanasia’ or is this something that can be managed medically,” she said. “Keep an open mind. Don’t focus on one diagnosis; if that horse is not responding—it is still in pain—you need to revisit your diagnosis.” She said that medical versus surgical treatment is a grey area. “There are all kinds of parts to the jigsaw puzzle. Unfortunately, there is not a nice checklist that will guarantee that you can diagnose every medical or every surgical colic.”

Collecting the pieces

Even in the field, there are many aspects of the problem that can be measured, so take advantage of these clues to decide this “complex jigsaw puzzle,” she said. A rectal examination can provide a good deal of information, according to Prof. Archer because the pelvic flexure is frequently a site for impaction. If there is an obstruction, the veterinarian of-

Table 1: Specifications for 3 portable analyzersused for measuring lactate concentration Lactate Pro ** Lactate Plus Lactate Scout Price $471 $275 $475 Cost/Strip $2.80 $1.84 $2.08 Refrigeration of strips No No Yes Sample volume (µL) 5 0.7 5 Analysis time (second) 60 13 10 Range (mmol/L) 0.8–23.3 0.2–25 0.5–25 Quality control Check and calibration strips Quality control solutions (2) Quality control solution (1) 8

Issue 11/2015 | ModernEquineVet.com

ten can palpate the distended bowel during the rectal examination. “It is not uncommon for us to get small obstructional cases coming in that are only recognized when rectal examination is performed,” she said. Many structures can be palpated, parts of the large colon, including the pelvic flexure, the caudal part of the spleen and left kidney, the bladder, inguinal rings, the cecum and segments of the small colon. The root of the mesentery and the nephrosplenic ligament may be palpable, but the small intestine may not be palpable unless it is distended. “People sometimes confuse a large colon impaction with a cecal impaction,” Prof. Archer said. “Remember a cecal is on the right side. Also it is important to differentiate a primary large colon impaction [feels large and smooth] from a secondary impaction, which is commonly due to a small intestinal obstruction [feels more corrugated].”

Benefits of nasogastric intubation

Nasogastric intubation can easily be performed in the field and is a valuable part of the puzzle. More than 2 L of net reflux is significant. However, it can take hours for fluid to back up into the stomach in the case of a small intestinal obstruction. So, just because there is no reflux, it does not mean that there are no obstructions, according to Prof Archer. Nasogastric intubation can also be therapeutic. “Not only in a horse that has a stomach that is very full, you can decompress that stomach and reduce the risk of rupture, but there is good evidence in the literature that if you are very aggressive with those large colon impactions, oral therapy has a successful outcome in those cases,” she said.

Assess the peritoneal fluid for color, cloudiness, specific gravity, total protein and lactate, some of which can all be done in the field with the eye and a portable analyzer. Assessment of peritoneal fluid can provide information about the disease process especially in the early stages. For instance, strangulating obstructions can produce peritoneal changes before a horse even shows marked deterioration in clinical parameters. “I always feel a little bit better when I know I have normal peritoneal fluid. It is just another bit of information for the puzzle,” Prof Archer said.

Obtaining a sample

Obtain the sample by doing an abdominocentesis. Dr. Archer tries to stay near the midline, which is a little thinner than the rest of the abdomen. “Some people go slightly off to the right to try and avoid the spleen but this is a pretty safe procedure. But I have seen a couple of cases of abdominal wall abscesses and I wonder if they had stayed midline, it might have been a little bit

safer,” she said. One can use a needle, which is quick and easy. “The disadvantage is that the needle is only 1½ inches long and sometimes you do not obtain a sample because the needle is simply not long enough to get through the body wall and penetrate the peritoneal cavity,” said Dr. Southward, who uses a T-cannula because it is longer. Although its length better enables the veterinarian to obtain a sample, the veterinarian must do a stab incision to get through the wall, so the horse will need to have a small amount of local anesthetic injected into the skin at the site. “If I want to do quick and easy, I do an abdominocentesis with an 18-guage needle, if I want that sample and I didn’t get it with a needle, I will move on to using a T-cannula,” she said. Assess the peritoneal fluid for color, cloudiness, specific gravity, total protein and lactate, some of which can all be done in the field with the eye and a portable analyzer. “How do we interpret the fluid that we get? We can look at it. Number one is color. Normal peritoneal fluid is clear yellow. If you get serosanguinous fluid, there is a strong association with the need for surgery. How can you tell if it is contamination? When it is contamination there is often a little streak of red in your sample to start with, and then—when the fluid starts flowing—it is clear yellow,” Dr. Southward said.

Measure lactate

Dr. Southward finds lactate to be particularly helpful. Peritoneal fluid is an ultrafiltrate of plasma and lactate is the end product of anaerobic metabolism. So when cells don’t get enough oxygen to undergo anaerobic glycolysis, ModernEquineVet.com | Issue 11/2015

C0ver story

they will produce lactate. High lactate levels can indicate an intestinal strangulation, she said. Lactate can be measured with a handheld point-of-care meter, according to Prof. Archer. Veterinarians at the University of California Davis compared three meters (Vet Surg 2015 Apr;44(3):366-72). They found that there was some variation among analyzers, so get to know your piece of equipment to interpret the results. “That is important when you decide to cut off? values with your meter versus what you find in the literature. So you need to know your meter,” Prof. Archer said. “We do use ultrasound on most of the colic cases that come in,” Prof. Archer said. “But in the field in the winter, there are time considerations. Horses have a long hair coat and I don’t want to spend an hour clipping a horse. That would be wasting valuable time. So, it can be a useful tool if you have time to use it.” The results can provide early clues about the need for surgical intervention. “You can see much more than you can feel on rectal examination,” Prof. Archer said. “With all of these tests, you have to interpret it with all of your

Put together all

is going on and surgery might be an option.

the pieces for a

Communication is key

coherent picture of the colic. clinical findings. History, physical exam and all diagnostic tests, and then put them together and it has to make sense,” she said.

Reassessment

If the case is going to be managed medically, think about analgesia and fluids, Prof. Archer suggested, and repeat the evaluation in a few hours to make sure the animal is responding. “Reassessment is critical and it is more difficult in the field. Owner update can be highly variable. What one owner will classify as mild is very different from another’s [assessment],” she said. If the horse is not responding to analgesia and is still in pain, consider referral. Flunixin is a great drug, but be careful for horses with mild-to-moderate pain when you don’t know what

Make sure there is good communication with the caregiver. They need to understand what is at stake—that this could be life threatening—and when to call you back. “You’ve got an owner who is a gatekeeper to that horse’s care. You also have that soothsayer in the yard that has seen everything and has an opinion on everything [saying], ‘No, you don't want surgery.’ So, it is essential to have clear communication about what is going on,” she said If the horse does well, remember that one-third of horses will have a recurrence in a year. Once that horse’s medical colic is resolved, check its teeth for massive enamel points, check tapeworm status, check for sand if you live in a sandy region. Review the animal’s diet. “There is a lot that can be achieved in the field. Some aspects may be limited, but identifying that subgroup of cases that need to come into a clinic for surgery is key,” Prof. Archer said. Make sure that the horse is monitored and communicate with the owner for best results. MeV

Issue 11/2015 | ModernEquineVet.com

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Gastrointestinal Disease

Field strategies for treating colitis B y P a u l B a s i l i o

Colitis can be one of the more

challenging diseases to identify and treat in the field. Huge fluid losses and the threat of endotoxemia can wreak havoc on the horse or—in the case of a zoonotic etiology—an entire barn. At a recent meeting of the Northeast Association of Equine Practitioners in Pittsburgh, Pa., Rose D. Nolen-Walston, DVM, DACVIM (LAIM), focused on practical applications of a variety of treatment options for the clinician in the field. “Diarrhea tends to be more inflammatory in horses than in humans and small animals,” said Dr. Nolen-Walston, who is associate professor of large animal internal medicine at the University of Pennsylvania School of Veterinary Medicine. “If you have an owner who isn’t very experienced with horses, it can be difficult for them to understand that diarrhea is considered a serious medical emergency. In humans, if you have a case of diarrhea, you don’t

go racing to the emergency room. Clients need to know that they can’t wait for the horse’s diarrhea to clear up.” When an owner calls, the first thing Dr. Nolen-Walston wants them to check are the mucous membranes to see if they are red or purple. Ideally, the owner will also be able to check the horse’s pulse for a global view of how the horse is holding up against endotoxemia or dehydration. “If it’s between 44 and 60 beats/ min, the horse needs to be seen within a few hours,” she said. “If it’s greater than 60, then the animal should probably be brought right in. If it’s more than 80, then I need to have a serious talk about decompensation.”

Lactate—the body’s scorecard

Measurement of lactate is one of the easiest ways to determine whether the clinician is winning or losing against the condition. A commercial handheld lactate meter costs approximately $375, plus $2 per strip.

Enteral fluids Enteral fluids are gaining popularity with clinicians who prefer to use large amounts of tap water with “do-it-yourself” electrolyte recipes instead of prepackaged sterile saline. One way to administer these fluids is to place a regular nasogastric tube in the horse once daily, or tape it in place, give the owner a funnel rather than a pump so that he or she cannot easily overfill the horse’s stomach. The tube can also be taped into place and the horse can be hooked up to a coil set. However, with a regular-size nasogastric tube, the horse will be unable to eat. “The other way is to use a thin, dedicated enteral feeding tube so that the horse can still eat,” she said. “I like to keep the horses eating hay or something bulky to fill the GI tract. These tubes can be hard to pass into the stomach, and horses love rubbing them out of place at horrible times, usually overnight.” To keep the tube in place, Dr. Nolen-Walston will use the stiff, plastic U-shaped tube that comes with the package. It is designed to be taped to the halter so that the tube is held firm in the horse’s nostril. “I will then get a large amount of nylon suture on a straight needle and sew that tube in place like I am trying to make a quilt. About half of the time, they’ll still end up rubbing the tube out.” ModernEquineVet.com | Issue 11/2015

Gastrointestinal Disease “Lactate is the body’s scorecard. The body’s tissues need to be perfused, and lactate tells you if you’re successfully perfusing the horse’s tissues,” Dr. Nolen-

Walston said. “It’s worth the money to see whether the horse is still compensating for dehydration and endotoxemia from colitis, or if it is heading down the

road to organ failure.” Normal lactate levels are typically <1 or <2 mmol/L. Between 2 and 4 mmol/L means the tissues are likely not being perfused. In

Common Causes of Colitis Rose D. Nolen-Walston, DVM, DACVIM (LAIM), offered up a quick reference guide for the common causes of colitis, what they look like, and how to diagnose them. 1. Potomac Horse fever What it looks like: • Fevers to 104° F. • Significant leukocytosis. “With other causes of colitis, they may founder on day 3 or 5 because they’ve had sudden inflammatory response syndrome [SIRS] for a while. With my Potomac Horse fever cases, they will often have laminitis before the diarrhea even starts.” How to diagnose: • Blood or feces PCR “Treat with oxytetracycline before you get the results back. If Potomac Horse fever is suspected, treat first and ask questions later.”

How to diagnose: • Fecal PCR. “Even after they recover, these horses can shed the virus in feces for 2 weeks. They must stay isolated until they are negative.”

2. Clostridium difficile and C. perfringens What it looks like: Symptoms range from mild to very severe, usually after antimicrobial treatment. • Bloody diarrhea may be present in foals. How to diagnose: • Toxin ELISA or PCR. “There is no point in using culture for these horses. Horses have Clostridium sp in their feces normally.”

6. Larval cyathostomiasis What it looks like: “We tend to overdo deworming in horses, and we are starting to cause some very resistant parasites. This condition is caused when the encysted larvae all come out of the horse at once. The horse will have marked diarrhea and profound hypoproteinemia. How to diagnose: • Fecal egg count is not useful; the larvae cause disease. • Thickened colon on ultrasound and red larvae in manure and on sleeve. • Treat with moxidectin and steroids.

3. Salmonella sp What it looks like: • High fever, occasional reflux, profound leukopenia and no appetite. How to diagnose: • Fecal PCR. • If salmonellosis is suspected, the horse must be isolated.

Photos courtesy of the CDC

4. Coronavirus What it looks like: • Fevers to 105° F. • May have mild colic and mild diarrhea with profound neutropenia without the appearance of being ill.

Issue 11/2015 | ModernEquineVet.com

5. Cantharidin toxicosis What it looks like: • Diarrhea, colic and hematuria. • Marked hypocalcemia. How to diagnose: • Ask owners if the horse has received Western Alfalfa hay. • Find the beetles.

7. Small colon impaction What it looks like: • Can “masquerade” as colitis; low volume diarrhea, colic and fever are present. How to diagnose: “On rectal examination, it will feel like an anaconda in the abdomen.” 8. “Colonic dysbiosis” What it looks like: • An episode of colitis where the etiologic agent cannot be determined. How to diagnose: • Diagnosis of exclusion.

humans, the criteria for shock is anything >4 mmol/L. If the level is between 8 and 12 mmol/L, the horse is nearing the point of no return. Anything >12 mmol/L means the horse is probably within hours of death, often even with treatment.

Hematology

Although results may not be available immediately, running bloodwork in the field does have value. Horses with colitis will frequently have a leukopenia that is characterized by neutropenia, but concern is warranted if bands are present. “Adult horses do not like making bands,” Dr. Nolen-Walston explained. “If there are any bands at all, you will most likely see something bad happen during the next 24 hours. Bands bode poorly.” The end stage of colitis often involves disseminated intravascular coagulopathy (DIC), as the animals will develop an asymptomatic thrombocytopenia. “You’ll often see clumping on a sample, so you may not be able to hang your hat on a single platelet count performed by an analyzer. If you see a true thrombocytopenia, then that is usually a bad prognostic indicator.” Dr. Nolen-Walston starts to get concerned when PCV goes up and total protein goes down, as fluid resuscitation will cause the total proteins to plummet. She noted that she does not tend to worry until the total protein level is <4 g/dL, and giving small amounts of plasma at that point is not likely to be of benefit as colloid replacement therapy.

Serum chemistry

“In my experience, horses with colitis always seem to have a serum sodium concentration of 126 mEq/L,” she said. “It’s not 100% true every time, but it is true way more often than you would think. There must be some other mechanism involved where the kidneys

really start to kick in at that level.” Dr. Nolen-Walston noted that if a horse’s sodium level is <128 mEq/L, then monitoring is indicated. At a level <125 mEq/L, treatment for hyponatremia should be initiated. If the level is <118 mEq/L, then a call to an internist might be a good idea. “If you have a horse with colic and a sodium concentration of 126 mEq/L, then it may be time to put that horse in a diarrhea (isolation) stall rather than a colic stall, because there’s a good chance the colic is from an impending colitis. It’s especially true if there are other signs of systemic inflammation, including dark mucous membranes, fever, or leukopenia” Many of the horses with colitis will present with a prerenal azotemia that is corrected easily after 1 or 2 days of treatment. “We do need to be aware that a lot of the treatments such as flunixin, oxytetracyline, and polymyxin B we give these patients are tough on the kidneys,” she said. “Things can convert from prerenal azotemia to true acute tubular necrosis fairly easily. Keep monitoring creatinine, and if it starts creeping up then you should probably change what you’re doing.”

Treatment in the field

The most relevant action a clinician can take to save an animal’s life in the field is to administer fluids, and Dr. Nolen-Walston prefers to “go big or go home.” However, farm structures and portability concerns can limit the amount of fluids that can be hung for a horse with highvolume losses. “The minimum amount of dehydration we can assess clinically is about 5%, which is a loss of about 20 L in the horse,” she explained. “These horses can have diarrhea losses of 5 L per hour. If you’ve only got one 5 L bag, then you need to pick a different way of giving fluids [See Box on page 11].”

Dr. Nolen-Walston tends to use hypertonic saline as a “Band-Aid” measure in horses that are markedly hemodynamically compromised. However, she stated that if she is going to need to follow the hypertonic saline with crystalloids anyway, then she might as well just start with the crystalloids if they are available in sufficient volumes to fluid resuscitate the patient.

Additional therapies

“I don’t know how much of a difference the endotoxic therapies make, but I don’t think many of us are brave enough to see what happens when we stop using them,” Dr. Nolen-Walston said. One of the therapies that is effective is polymyxin B, which is given at low doses to bind the endotoxin in the blood. A less expensive alternative is flunixin, which has additional anti-inflammatory properties. Smectite clay (Biosponge), given enterally, binds clostridial toxins in the lumen of the colon, but the evidence in the veterinary literature is sparse. One therapy that is gaining traction in human medicine is fecal transplantation from a healthy donor. Dr. Nolen-Walston has started doing more of these, but there is a complete lack of evidence in the literature. “I will give the horse omeprazole 12 hours before the transplantation to give the stomach a more neutral pH level. I will also try to find a donor horse from a similar barn environment so that they will theoretically have a similar gut biome.” She will then make a slurry of fresh manure and administer a 2 to 6 L dose to the affected horse, but noted that she does not know if that is necessarily the correct amount that should be given. “This is something that is cheap and easy, and if you look at humans, the results do suggest efMeV ficacy,” she concluded. ModernEquineVet.com | Issue 11/2015

Holistic medicine

Integrating acupuncture

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Photo courtesy of Dr. Leich

Acupuncture is an adjunct

to, not a replacement for, the treatment of horses, according to a holistic veterinarian who now devotes her practice to treating horses with acupuncture and Chinese herbal medicine. Wendy Leich, VetMB, CVA, said she was drawn to acupuncture while she and her husband Brendan Furlong, MVB, MRCVS, were caring for horses with the United States Equestrian Team. “We were looking for anything that could give us an edge with these horses in terms of managing them in the competitions. At the top level of competitions very few medications are allowed, and drug testing has become more and more sophisticated,” said Dr. Leich of BW Furlong and Associates in

Issue 11/2015 | ModernEquineVet.com

K a t h l e e n

O g l e

Oldwick, NJ. “We discovered that dry needle acupuncture is perfectly legal and allowed under FEI [Fédération Equestre Internationale] drug rules.” With a long-time interest in alternative therapies, such as massage and chiropractic, she chose a yearlong equine program at the Chi Institute of Traditional Chinese Veterinary Medicine in Reddick, Fla., where she trained with the school’s founder, Huisheng “Shen” Xie, DVM, PhD. “I’ve always been very interested in trying to find ways to make horses perform at the best of their ability, stay comfortable and be happy in my work,” she said. “There is quite a big spectrum of things that one can do to be helpful to horses.”

As a scientist, she found the program challenging. “It is like learning a whole new language,” she said. Initially, she was also somewhat skeptical. On the first day of class, she received an acupuncture treatment, in which her instructor placed several needles in her arm, for a large bruise she received after falling from a horse. But when she woke up in the next morning she said the bruise was nearly gone. The course, which is for licensed veterinarians, involved spending five to six days at a time at the school as well as reading assignments, written case reports and exams. In addition, she was required to spend a certain number of hours with a certified acupuncturist. Acupuncture, which is derived from the Latin words “acus” for

into the veterinary care of horses

needle and “punctura” for pricking, is one part of traditional Chinese medicine, as are herbal medicines, nutrition and massage. The basic concepts, which include balancing yin and yang, Qi, and five-element theory, she said, have been around for nearly 3,000 years.

Scientific basis

Over the past 20 years, there has been growing interest in understanding acupuncture from a neurophysiological approach. Dr. Xie, who trained Dr. Leich, has been working with the University of Florida, College of Veterinary Medicine in Gainesville, to study the scientific basis for acupuncture and electroacupuncture, as well as Chinese herbal medicines. “We know that acupoints are active points with electrical resistance and electrical conductivity. We

know that when we stimulate these points we can produce chemical and hormonal changes throughout the body,” Dr. Leich said, adding that as of 2010, PubMed listed 18,917 acupuncture references of which 282 are veterinary references. “We can change brain function,” she said, pointing to MRI studies of human patients who were experiencing pain and received acupuncture. “After acupuncture you do get quite pronounced changes in brain chemistry.”

No placebo effect in horses

Unlike in human patients, there is no placebo effect in horses. “The nice thing about horses is that they don’t fake it for you,” Dr. Leich explained. “They either like what you do to them or they don’t. The majority of horses tell me very clearly that their brain energy is changed.

They get a tremendous endorphin release—they start to lick or chew, drop their head, yawn. A lot of them look like they have been sedated. It’s very interesting to watch a horse’s response. The horses tell you whether you are making a difference.” According to Dr. Leich, acupuncture promotes the body’s ability to heal itself. To describe the difference between traditional Chinese medicine and Western medicine, she uses the example of a cough. “Chinese medicine would say there’s something wrong, in this case maybe dry heat in the lung would be the Chinese root cause of the cough. We would use acupuncture and Chinese herbs to clear the dry heat from the lungs. In Western medicine we say you have a cough, we have to give you a cough suppressant to stop your coughing,” she said.

Practicing acupuncture.

ModernEquineVet.com | Issue 11/2015

Holistic medicine

Another advantage to traditional Chinese medicine and acupuncture is that there are very few potentially harmful side effects. “When you start using Chinese herbs there is potential for some side effects but with acupuncture it either works or it doesn’t,” she said.

Basic Concepts of Traditional Chinese Medicine Balancing Yin and Yang • Yin is female, weak, passive, and dark. • Yang is male strong, active, and bright. While yin and yang are polar opposites, they are also complementary and interdependent. There is no dark without light, no weak without strength. Although the polar opposites are different they are related. If one is much stronger than the other in a body then there is going to be an imbalance. When trying to manage disease in Chinese medicine the goal is to maintain balance. Qi Qi is the force or energy that controls harmony in the body. If there is pain there is a disharmony of chi in the body. The Qi or the energy moves through these different pathways which are known as meridians during the 24-hour period of the day. If the circulation of Qi is blocked, there is stagnation, which means the energy is not flowing. The insertion of a needle into the correct acupuncture point can relieve the stagnation and allow the Qi to circulate freely and the body to heal itself.

Issue 11/2015 | ModernEquineVet.com

Then she returns with the needle cap to scan the meridians one more time to check that everything feels comfortable and there are no more diagnostic points. She leaves the needles in for 10 to 15 minutes and can work on a second or third horse while the others are “cooking.” “One of the things that is really interesting is that when the energy starts to flow through the meridians the needles start to push their way out,” she said.

Black blood

Dr. Leich noted that she will become very excited when she sees a drop of black blood upon removal of an acupuncture needle. “In traditional Chinese medicine, that means I relieved stagnation in that meridian or that site,” she explained, adding that “You only get the black blood that is very specific for that horse and that problem.” For example, she might get black blood on the heel point of a horse with navicular disease, or on the hock point of a horse with sore hocks, or a stomach point for a horse with stomach ulcers. “When you see that, it tells you, from a Chinese perspective, that your working diagnosis was correct,” she said. “The horse is telling you ‘Yes, that is what was bothering me.’ When you get those drops of black blood you will usually get a dramatic improvement in the horse’s status.” Dr. Leich charges $168 for an acupuncture treatment plus a stable visit fee. She tries to schedule two or three horses a visit so that the stable fee can be shared among the owners, as well as to make effective use of her time. For more information about the Chi Institute, MeV visit www.tcvm.com.

Click here to watch video

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Five-Element Theory The five elements are Wood, Fire, Earth, Metal and Water. They correspond to five different personality types, and they also correspond to phases of life. In addition, bodily organs have been mapped to the five elements. Wood: Ultimate competitor; baby; demanding; anger; tendons and eye problems. Fire: Perfect show horse; teenager; social; excitable; heart and hormonal system. Earth: Lesson horse; reliable; friendly; stomach and digestive system. Metal: Ranch horse; hard working; sense of fairness; lungs. Water: Arab park horse; submissive; fearful; kidney, nerves, ears, bones.

Dr. Leich emphasized the need to have a correct diagnosis. “I like to have a discussion with the owner first and find out what’s going on with the horse, the reason they called me in, what the problems are, case history and then I do a proper exam. I don’t suggest that acupuncture is the only treatment. I get quite frustrated when I go to meetings and I hear veterinarians say they never use a stethoscope. I definitely like to incorporate acupuncture into veterinary practice. I want to stress that it’s an adjunct, not replacement,” she said. When administering acupuncture, Dr. Leich always has someone hold the horse. She then uses a needle cap to palpate the different meridians, which according to traditional Chinese medicine are the pathways through which energy flows. While palpating, Dr. Leich observes how the horse responds. To help train herself, Dr. Leich would do acupuncture reads on horses before they underwent a bone scan. “I got to the point where I was very comfortable— more than 90% of the time—to come up with the same things with my needle cap scan as I did with the bone scan. That was part of the way I trained myself to figure out what I was reading on these horses,” she said. After the needle cap scan, she uses a chiropractic activator on the horse. Starting at the horse’s neck, she makes three passes with the high-velocity, low-impact activator. The activator enables the acupuncture to last a little bit longer, she said. Starting at the neck again, she places the needles according to her findings on the needle cap scan.

news notes

Emptying the distal limb vasculature using an Esmarch bandage prior to antimicrobial IV regional limb perfusion (IV-RLP) increases the immediate amikacin concentrations in the synovial fluid of the metacarpophalangeal joint, according to researchers at the University of California Davis College of Veterinary Medicine. Although this is commonly done in human patients to prevent the leakage of solution under the tourniquet, the researchers wanted to determine whether exsanguination of the distal limb prior to IV-RLP increases antimicrobial concentrations in the synovial fluid in horses. Eight sound horses underwent IV-RLP with amikacin sulphate on two occasions; once with prior distal limb exsanguination and once without. The pneumatic tourniquet was placed approximately 10 cm proximal to the accessory carpal bone and exerted a standardized amount of pressure (450 mmHg). A solution containing 2 g amikacin sulphate in 60 mL sterile saline solution was infused over a period of one minute into the cephalic vein distal to the tourniquet and the tourniquet was left in place for 30 minutes after the infusion. Venous blood samples were also taken one minute before tourniquet removal. Synovial fluid was obtained from the radiocarpal and metacarpophalangeal joints at five minutes and 24 hours. Concentrations of amikacin in synovial and blood samples were determined using an immunoassay. Concentrations of amikacin sulphate in the metacarpophalangeal joint at 5 minutes were significantly higher in the exsanguination group than in the nonexsanguination group. This difference was no longer present at 24 hours. There was no significant difference in the amikacin concentrations in plasma or in radiocarpal joint fluid at either time point. The researchers postulated that the higher concentration of amikacin in exsanguinated limbs immediately after IV-RLP may be the result of decreasing the blood volume in the limb, resulting in the amikacin being less diluted by the blood and therefore reaching higher concentrations in the vasculature. This might be important when employing concentration-dependant antimicrobials such as amikacin. Emptying of the vasculature may also result in faster

Courtesy of the Equine Veterinary Journal

Tourniquet for IV-RLP increases joint drug concentrations

Emptying the distal limb vasculature using an Esmarch bandage prior to antimicrobial IV-RLP increases amikacin concentrations in the synovial fluid.

diffusion of antimicrobial solution and reduced risk of leakage of the solution under the tourniquet. Further study is required to determine whether these effects are also observed in horses with diseased or inflamed joints, the said. MeV

For more information: Sole A, Nieto JE, Aristizabal FA, Snyder JR. Effect of emptying the vasculature before performing regional limb perfusion with amikacin in horses. Equine Vet J. 2015 (Epublished ahead of print Oct. 9 2015 DOI: 10.1111/evj.12501 http://onlinelibrary.wiley.com/doi/10.1111/evj.12501/abstract.) ModernEquineVet.com | Issue 11/2015

AAEV T M E M b E r s h i p Membership in the AAEVT is open to all veterinary technicians, assistants, support staff and those employed in the veterinary health care industry worldwide. Student membership is open to those currently enrolled in an AVMA/CVMA accredited veterinary technology program.

AAEVT Membership • • • • • • • • • • •

Bi-Annual Newsletter Weekly “HoofBeats” Email Newsblast Full access to www.aaevt.org, including the Career Center and the Library Up-to-date information on the AAEVT Discounted registration for AAEVT Regional Meetings and the annual AAEP/AAEVT Convention NTRA, Working Advantage and Platinum Performance Benefits The opportunity to participate in the AAEVT Online Certification Program or to become a member of the AEVNT Academy-Specialty in Equine Veterinary Nursing Scholarship opportunities. AAEVT’s Equine Manual for Veterinary Technicians (Blackwell Publishing 20% discount on purchase price) Opportunity to attend Purina’s Annual Equine Veterinary Technician Conference - All Expenses paid!

AAEVT Objectives • • • •

Provide opportunities for CE, training, communication, and networking Educate the equine veterinary community and the public about our profession Inform Members of issues affecting our profession Assist in providing the best medical care to improve the health and welfare of the horse

AAEVT Online Equine Certification Program

• A three course, 10 module, equine-only online program offered through ACT • Geared toward Credentialed Veterinary Technicians, Assistants, Support staff, & Students • Areas of study include: equine medical terminology, anatomy and physiology, parasitology, laboratory, diagnostics, equine basics (breeds, wellness, husbandry,) diagnostic procedures, emergency medicine, restraint, pharmacology, surgical assistance and anesthesia, equine office procedures • A certificate of completion is awarded to those who: Successfully complete required courses Complete the list of required skills (per a supervising DVM who is an AAEP member) Attend an AAEVT regional CE symposium and participate in the we labs • Those individuals who successfully complete the programs will be recognized as AAEVT Certified Equine Veterinary Technicians / AAEVT Certified Equine Veterinary Assistants depending on their current designation. The certificate is recognized by the AAEVT and the AAEP but does not grant the credentialed status by the AVMA • For more information go to www.aaevt.4act.com or call 800-357-3182

AAEVT Mission Statement: To promote the health and welfare of the horse through the education and professional enrichment of the equine veterinary technician and assistant.

Fo r m o re i n f o r m a t ion v ist w w w.a ae vt.or g

*American Association of Equine Veterinary Technicians and Assistants

technician update

5 Tips Large Animal Hospital for the

After several years as a veterinary technician in a busy referral clinic doing equine medicine and having the opportunity to travel and visit other hospitals as well, I have learned a few ways to make our jobs easier. Here are some tips that I have learned and hope you find useful in your practice too.

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B y S u e L o l y, LV T, V T S - E V N

Patient Identification — Have you ever heard? “Can someone bring the bay horse to radiology?” Which one, they all look the same? Labeling equine patients has not been an easy task in the past. Many small animal hospitals use soft and comfortable ID collars made of strong spun bonded olefin (EJay or KVP brands). Take the 20" bands, cut in them half, then fold each piece with a small elastic or hair band in the middle, then tape the end together. They can be written on either side with permanent marker or you can stick your patient label directly on them—easy to wrap into a patient’s mane to provide identification.

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Make troubleshooting equipment easier — With so many different pieces of equipment, it’s hard to keep everyone up-to-speed on troubleshooting when things go wrong. Just moving equipment around can cause parts to come loose or undone. An easy trick to help avoid plugging the wrong parts together is to use colored label tape to match up which cord plugs into which outlets. You can use instrument label tape—the same tape that is used to wrap around and identify surgery instruments. Wrap the tape around the cord and place a corresponding piece near the plug-in.

Keeping track of your thermometer — This is especially helpful for when you want a thermometer dedicated to a specific patient during their care. Simply take a syringe case from a 6 cc, 12 cc, or 20 cc syringe and attach it to the front of the patient’s stall with a little bit of tape. It gives the syringe case a second purpose and can still be recycled when you’re done. Making light work of heavy lifting — Repeatedly lifting heavy bags of IV fluids or large carboys can be strenuous. Weights of 20 L of IV fluids in a bag or a heavy carboy can easily exceed 50 lbs. Most clinics have a very simple single pulley to use, putting most of the strain on the person pulling or lifting. Instead, set up block and tackle systems for fluids. This is a mechanism consisting of ropes and one or more pulley-blocks used for lifting heavy objects and can be found at a hardware store. The block part of the system can help hold or lock items in place—even temporarily—so so one can take a break or readjust their grip and helps control the downward force of gravity. When the system is empty, it can be helpful to have a small weight at the top or a hook on a long handle for pulling the system down when needed.

Drying and storing your 3 m endoscope safely — Check out this great idea: use a cut PVC pipe secured to the wall at an angle running the length of the scope tubing. It allows for the endoscope to drain and dry in a safe and secure out-of-the-way place. Do away with hanging them to dry and having to pack them back in the case later. MeV

About the author

Sue Loly, LVT, VTS-EVN, is the Large Animal Technical Supervisor at the Leatherdale Equine Center, the University of Minnesota. She is also the incoming president of the AAEVT.

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