The Modern Equine Vet - July 2023

Managing Gastric Illness

Treating Fungal Endometritis

Assessing Emotions in Wild Horses

Technician Update: Breaking the Pain Cycle of Kissing Spine

SALES: ModernEquineVet@gmail.com

EDITOR: Marie Rosenthal

ART DIRECTOR: Jennifer Barlow

CONTRIBUTING WRITERS: Paul Basilio • Rob Warren

COPY EDITOR: Patty Wall

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THE

MANAGING

Gastric Illness

Nonpharmacological Management of That Unique—and Frustrating—GI Tract

By Marie Rosenthal,MS

The management of equine gastric diseases is one of those cases where prevention is better than cure, according to Galye Hallowell, MA, VetMB, PhD, CertVa, DACVIM, DACVECC, DECVSMR, PFHEA, FRCVS, a professor at the University of Nottingham, in England.

Preventive measures include diet and perhaps environmental changes that could address the horse’s stress. However, not all nonpharmacologic management remedies are created equal.

“When we are thinking about management, we really think about prevention as well as our acute phar-

macologic management,” Dr. Hallowell said at the recent ACVIM Forum 2023. “And where preventative measures are concerned, think about the diet, but also about other management changes.”

She gave what she acknowledges was a rare example. She had a patient, a 9-year-old Andalusian stallion, who used to be a breed horse. He was turned out in a paddock near a variety of mares, but there was an electric fence around it. He could not touch the other horses. After trying multiple things for his severe glandular disease, she recommended they move him away from the mares.

“When he got turned out, he had paddocks all around him where he was surrounded by mares in the summer. So, we had a chat about the fact that this was probably a relatively stressful environment for him,” she said, because he couldn’t breed with these mares.

“We moved him to a yard where he was with 2 other geldings. There were no mares,” she said. When she rescoped him 8 weeks later, his behavioral changes had gone, and his glandular disease had gone, and he received no therapy. And in fact, the only thing I did was move him away from mares,” she said.

In addition, nonpharmacologic management may be cheaper than prescription medication. “If we can get these nonpharmacologic therapies to work, we should hopefully improve affordability of treatment, and, perhaps in some cases reduce our reliance on antimicrobial use, which is going to become more important as time moves on.”

The risk factors and management of equine squamous gastric disease (ESGD) are well understood and include dietary changes, turnout on pasture, providing small amounts of forage before exercise and minimizing stress. Corn, safflower and other oils containing omega 6 fatty acids, which may be useful for ESGD. Fish oils, which contain omega 3 fatty acids, might also be useful. The data show horses that received those safflower oil and/or fish oil supplements, which are higher in omega fatty acids, had a much lower prevalence or no ESGD, and when it did have squamous disease, the grade was much lower, she said.

“Corn oil might be beneficial,” Dr. Hallowell said. “Certainly experimentally, it decreases gastric acid output and increased prostaglandin E2. The omega 6 safflower and fish oils may be more beneficial, and I think we need to watch this space,” as more people are researching it.

Some studies have looked at sea buckthorn berries, which are rich in large numbers of nutrients, and people have found that they might reduce ulcer scores. However, the jury is still out on glandular disease. Continual use may worsen disease, rather than improve it.

Another more recent study looked at a seaweed derived calcium supplement. Although it did have an

impact on gastric pH, the effect was short acting. “It's probably not causing acid suppression for anywhere near the amount of time we would need to see any form of clinical improvement,” Dr. Hallowell said.

Aloe vera is another product with very beneficial properties. One study compared it to omeprazole for glandular disease, but she said that might not have been a fair comparison. The aloe vera provided some healing and improvement rates but they were lower than omeprazole, according to Dr. Hallowell. “But obviously they were never going to be equivalent, which is no surprise to any of us, I'm sure.”

Pectin-lethicin could be used as a mucosal protectant, but there is no evidence that it's going to be beneficial for healing. But it might be good in the armamentarium for protecting against disease.

IBD Appears to Be Increasing

Anecdotally, the prevalence of irritable bowl disease (IBD) is increasing among horses, but it’s hard to know whether it is an increase in disease or just better recognition, she admitted. Horses with IBD can present as recurrent colic, can present with anorexia and unexplained weight loss, and sometimes with diarrhea. “I would say I see weight loss most as a presenting sign,” she said.

Intestinal wall thickness on ultrasonography, documentation of malabsorption, as well as rectal and or duodenal mucosal biopsies are used typically to diagnose IBD.

Genetics, the environment, exposure to bacteria, viruses and parasites, and diet can all play a role.

Steroid or azathioprine are frequently used to control inflammation, but if other management is not provided, “we're setting them up to fail or to get recurrence,” Dr. Hallowell said.

In people, early use of antimicrobials has been shown to alter the intestinal microbiome, which can increase the risk for Crohn’s disease or IBD, she said. Breast feeding is found to be protective.

“And we know that fiber and olive oil are usually protective, and that stress is a risk factor,” she said.

“The other thing that we know is that dysbiosis plays a pretty big role in IBD in both people and dogs, so we assume it does in horses,” she said.

It's perhaps not quite as clear yet, but it is a large area

Genetics, the environment, exposure to bacteria, viruses, parasites and diet can all play a role in gastric illnesses.

GI DISEASE MANAGEMENT TIPS

Preventive measures

• Evaluation and manipulation of diet

• Other management changes

Nonpharmacologic therapies

• Improve affordability, if successful

• Reduce reliance on antimicrobials

•

Many promising products and concepts

•

REMEMBER: HORSES HAVE A UNIQUE, AND FRUSTRATING, GI TRACT

of research. “We're trying to get a real understanding of the normal microbiota, it's variation and also the things that change it,” she said.

They can have an impact on the microbiota in the short term, but whether they are able to make those medium- and long-term changes is also still a question.

Much of IBD management in dogs and cats focuses on exclusion diets, chicken-free and hydrolyzed diets. Many dogs and cats will respond to nutrition alone, she said.

Short-Fiber Diets

In her research, she found that short-fiber diets in horses should be easier to digest, and they may well form a different source of fiber to what the horse was exposed to before, which could be very important for IBD.

“The other thing with the use of short fiber diets is trying to simplify that diet and reduce the number of cereal proteins that horse is exposed to, particularly if those risk factors are similar to those in other species. We also know that the short fiber diets are going to be a lower volume, so it should be easier for them to move through the GI tract, particularly in animals that have gut motility disorders,” Dr. Hallowell said.

Although these short fiber diets may well have a place in horses with severe dental disease or mastication challenges, there might be a secondary impact on how that diet is processed in the GI tract.

She presented a study in 2020, where they looked over clinical case records of horses older than 6 years of age. They were looking for those with recurrent colic, which was defined as greater than 3 episodes in the previous 3 months with or without previous colic surgery and/or weight loss or diarrhea. They tried to determine weight over time and the overall outcome.

“These horses were feed a standard short-fiber diet that was split into 3 or 4 feeds per day,” she said.

The horse's weight was evaluated, and the diet was adjusted if they were gaining or losing weight. Some horses had access to pasture, and some did not depending on the time of year. They identified 32 horses between 8 and 22 years. They were predominantly Draft or Warmbloods; 53% were geldings and 45% were mares. Almost 40% had undergone colic surgery, 7%

for large intestinal displacement and partial torsions, and 25% for epiploic foramen entrapment.

The presenting signs were recurrent colic (69%), chronic or recurrent diarrhea (25%) and weight loss (6%).

They had motility studies for 88% of the horses, all those with recurrent colic, those with weight loss, and a few with diarrhea.

All the horses were fed a standard short fiber diet of alfalfa, unmolassed sugar beet, grass or other cubes and up to 50 mL vegetable oil for 6 weeks to 3 years.

The weight was maintained or increased slightly in 81% of horses, weight loss was seen in 19%.

Thirteen percent of the horses showed signs of colic while on the diet, and these horses died or were euthanized. Two horses were removed due to signs of abdominal pain and diarrhea, which abated when the diet was reintroduced.

“From this group, our 1- to 2-year survival was 80%,” she said.

“We didn't stop the diet in all cases to look at the impact of the diet or whether it was just mother time that improved matters. But what we did note was that it certainly seemed to resolve signs in 80% of cases,” Dr. Hallowell said.

Research is still be done on pre and probiotic, but so far, the efficacy data are really lacking, particularly for off-the-shelf items. Fecal transplantation has been used in practice for several decades, but that is also lacking evidence, she said.

“When we are thinking about nonpharmacologic management of GI disease, think about manipulation of the microbiome when we know more, maybe consider the short fiber diets and really think about the oils that we use,” she said. Gluten-free diets might be helpful as they are in some people.

Also, consider how antibiotics and antiparasitics in early life might affect the adult horse’s microbiome.

“I think there's lots of promising products and concepts, but we just need to interpret them appropriately,” Dr. Hallowell said. “And remember that extrapolation from other species might not result in success. It might, but we always must note the horse has got that unique if not frustrating gastrointestinal tract.” MeV

Treating Endometritis Fungal

A Closer Look at Difficult to Treat Fungal Endometritis

By Paul Basilio

Fungal endometritis is an important cause of infertility, and it carries a relatively poor breeding prognosis. These cases are often difficult to diagnose and to treat; luckily, they are not nearly as common as their bacterial counterparts, according to Tom Stout, VetMB, PhD, DECAR, a professor in the Department of Clinical Sciences at Utrecht University in the Netherlands.

Fungal endometritis, in essence, is an opportunistic infection. Causal organisms are found commonly in the environment—particularly in feces and on the skin—but the risk of clinical infection is vastly enhanced in mares with a chronically disturbed uterine environment, such as those with pneumovagina, necrotic foci, problematic foaling, and prolonged intrauterine antibiotic therapy.

According to some surveys, fungi account for only about 1% to 7% of all uterine infections. There is, however, a caveat, according to Dr. Stout.

“Do we always check?” He asked during a presentation at the 68th Annual AAEP Convention. “It may be that we’re not always culturing appropriately and picking them all up.”

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Reduce inflammation

Restore synovial joint lubrication

Repair joint cartilage

Reverse the disease cycle

When you start with it early and stay with it as needed, horses may enjoy greater mobility over a lifetime.2, 4, 5 Discover if Adequan is the right choice. Visit adequan.com/Ordering-Information to find a distributor and place an order today.

BRIEF SUMMARY: Prior to use please consult the product insert, a summary of which follows: CAUTION: Federal law restricts this drug to use by or on the order of a licensed veterinarian. INDICATIONS: Adequan® i.m. is recommended for the intramuscular treatment of non-infectious degenerative and/or traumatic joint dysfunction and associated lameness of the carpal and hock joints in horses. CONTRAINDICATIONS: There are no known contraindications to the use of intramuscular Polysulfated Glycosaminoglycan. WARNINGS: Do not use in horses intended for human consumption. Not for use in humans. Keep this and all medications out of the reach of children. PRECAUTIONS: The safe use of Adequan® i.m. in horses used for breeding purposes, during pregnancy, or in lactating mares has not been evaluated. For customer care, or to obtain product information, visit www.adequan.com. To report an adverse event please contact American Regent, Inc. at 1-888-354-4857 or email pv@americanregent.com.

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1 Data on file.

2 Adequan® i.m. Package Insert, Rev 1/19.

3 Burba DJ, Collier MA, DeBault LE, Hanson-Painton O, Thompson HC, Holder CL: In vivo kinetic study on uptake and distribution of intramuscular tritium-labeled polysulfated glycosaminoglycan in equine body fluid compartments and articular cartilage in an osteochondral defect model. J Equine Vet Sci 1993; 13: 696-703.

4 Kim DY, Taylor HW, Moore RM, Paulsen DB, Cho DY. Articular chondrocyte apoptosis in equine osteoarthritis. The Veterinary Journal 2003; 166: 52-57.

5 McIlwraith CW, Frisbie DD, Kawcak CE, van Weeren PR. Joint Disease in the Horse.St. Louis, MO: Elsevier, 2016; 33-48.

All trademarks are the property of American Regent, Inc.

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INFECTIOUS DISEASES

Diagnosis

Typical clinical signs include evidence of uterine inflammation, such as copious uterine fluid and vaginal discharge that can vary in color and consistency. Many mares with fungal endometritis are also barren at the start of the breeding season.

However, “there will be occasions where you see a mare with fungal endometritis that looks pretty normal and healthy,” Dr. Stout said.

Definitive diagnosis involves a combination of cytology and aerobic culture of uterine material obtained through a guarded swab, cytology brush or low-volume uterine lavage.

“You will need to culture [your samples] the right way,” he added. “That will typically involve Sabaraud’s agar or chromogenic agar.”

It’s important to note that a culture should not be declared negative for fungi until 5 days of incubation, as fungi tend to grow at a slower rate than other organ-

IS THERE A UTERINE BIOME?

In other structures of the body, such as the gut, excessive antibiotic use can disturb normal commensal flora and create an opening for an opportunistic infection.

“We’ve heard about the possibility of a uterine microbiome, and there have been a few studies that suggest there is a normal bacterial culture within the uterus,” said Tom Stout, VetMB, PhD, DECAR, a professor in the Department of Clinical Sciences at Utrecht University in the Netherlands. “But when we've tried to look, it’s challenging. The uterus of a diestrus mare seems to be sterile.”

He added that some sequencing techniques have found bacteria, but he’s unsure if that can be considered a real microbiome.

“It may be that we just can’t culture them, but I think there’s still a question of how important it is,” he said. “The issue [with fungal endometritis] is that as you put more antimicrobials in the uterus, they’re probably flowing back through the normal flora of the vagina and vestibulum. It may be that the colonization begins there, and then the next time you do something to the uterus, you’ll bring the fungi in.”

isms. For a more rapid diagnosis, Dr. Stout often turns to cytology.

“You’ll pick up neutrophils, and you’ll often see fungal organisms,” he explained. “It can be an extremely useful and quick way of making the diagnosis.”

Rapid typing and identification of the fungus is important for deciding on appropriate treatment. Many laboratories have specialized tests that can also identify fungal pathogens, but that process can take weeks.

“Occasionally, your swab will come back clean, and you may ask yourself why,” Dr. Scott said. “We think it’s because Candida albicans can grow intracellularly, and sometimes it can sit quite deep in the endometrium.”

Endometrial biopsy may also pick up evidence of endometrial fibrosis, which will impact the mare’s fertility prognosis.

Treatment

Fungal endometritis is a tricky infection to resolve, so naturally many different types of treatments have been attempted. The problem, however, is that not many veterinarians or clinics see enough of the cases to create large-scale, controlled clinical trials.

To help weed through the plethora of available choices, Dr. Stout gave a rundown of his typical treatment course.

First, he’ll do a uterine flush with 250 mg of 2% acetic acid. The acid is an irritant and will result in a sloughing of the endometrium.

“Sloughing of the endometrium may help antifungal treatments reach further into the affected tissues to get at that deeper seated fungi,” he explained.

After 5 minutes, he’ll flush out the acid with 3 L of lactated Ringer’s solution. Then, 50 mL of a 10-mg/mL clotrimazole solution is administered by intrauterine infusion for 6 consecutive days. Topical clotrimazole cream is also applied to the vagina and clitoris at the time of infusion.

“If we need to clean the uterus [on subsequent days], I’ll flush with the lactated Ringer’s solution before the clotrimazole administration,” he added. “That can be done daily.”

He explained that this treatment plan clears approximately half of the fungal endometritis cases he sees. It’s not perfect, but that 50% success rate is an improvement over past treatments, Dr. Stout said.

For the other 50% of cases that aren’t cleared, he will switch the clotrimazole to nystatin or amphotericin B.

Many mares with fungal endometritis are barron at the start of the season.

Break free

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24-hour Veterinary Technical Support available: (866) 933-2472

Nonurgent Technical Support available: support@dechra.com

Important Satefy Information

As with all drugs, side effects may occur. For intramuscular use in horses only. Not for use in humans. Pentosan polysulfate sodium is a weak anticoagulant. Caution should be used when administering Zycosan if you are taking an anticoagulant. In case of accidental self-injection, seek immediate medical attention. If product comes into contact with skin, rinse skin thoroughly with water and seek medical attention if needed. Horses with hypersensitivity to pentosan polysulfate sodium should not receive Zycosan. Do not use Zycosan concurrently with other anticoagulant drugs. Do not use in horses with clotting disorders or within 24 hours of surgical procedures. Caution should be used when administering this drug before or after strenuous activities. Caution should be used when NSAIDS are administered concurrently due to the anticoagulant effects of Zycosan. If Zycosan and NSAIDS are used concurrently, horses should be monitored for hemorrhage or other clinical signs of abnormal bleeding. The safe use of Zycosan has not been evaluated in breeding, pregnant, or lactating horses. The safety of long-term repeat use of Zycosan has not been evaluated. The most frequently reported adverse reactions are injection site reactions, prolongation of coagulation parameters (activated partial thromboplastin time (aPTT) and prothrombin time (PT). Refer to the prescribing information for complete details or visit www.dechra-us.com.

PFAS Found in Blood of Horses Living Near Fayetteville, NC

Elevated per- and polyfluoroalkyl substance (PFAS) levels in the blood of horses and dogs from Gray's Creek, N.C., including dogs that only drank bottled water were found by researchers from North Carolina State University.

The work establishes horses as an important sentinel species and is a step toward investigating connections between PFAS exposure and liver and kidney function in horses and dogs.

The study included 31 dogs and 32 horses from the community and was conducted at the behest of community members concerned about their pets' wellbeing. All the households in the study were drinking well water, and all the wells had been tested and deemed PFAS contaminated by state inspectors.

The animals received a general veterinary health check and had their blood serum screened for 33 different PFAS chemicals. These PFAS were chosen based on compounds that were present in the Cape Fear River basin and the availability of analytical standards.

From the targeted list of 33 PFAS of interest, researchers found 20 different PFAS in the animals. All the animals in the study had at least 1 chemical detected in their blood serum, and more than 50% of the horses and dogs had at least 12 of the 20 detected PFAS.

PFOS, a long-chain PFAS used for years in industrial and commercial products, had the highest concentrations in dog serum. The perfluorosulfonic acid PFHxS, a surfactant used in consumer products and firefighting foams, was detected in dogs, but not horses. Consistent with wells being the known contamination source, some ether-containing PFAS including HFPO-DA (colloquially known as GenX), were detected only in dogs and horses that drank well water.

In dogs who drank well water, median concentrations of 2 of the PFAS—PFOS and PFHxS—were similar to those of children in the Wilmington GenX exposure study, suggesting that pet dogs may serve as an important indicator of household PFAS. Dogs who drank bottled water, on the other hand, had different types of PFAS in their blood serum. However,

From the targeted list of 33 per- and polyfluoroalkyl substances of interest, researchers found 20 different PFAS in the animals.

16 out of the 20 PFAS detected in this study were found in the dogs who drank bottled water.

Overall, horses had lower concentrations of PFAS than dogs, although the horses did show higher concentrations of Nafion byproduct 2 (NBP2), a byproduct of fluorochemical manufacturing. The finding suggests that contamination of the outdoor environment, potentially from deposition of the PFAS onto forage, contributed to their exposure.

“Horses have not previously been used to monitor PFAS exposure,” said Kylie Rock, PhD, postdoctoral researcher at NC State and first author of the work. “But they may provide critical information about routes of exposure from the outdoor environment when they reside in close proximity to known contamination sources.”

Finally, the veterinary blood chemistry panels for the animals showed changes in diagnostic biomarkers used to assess liver and kidney dysfunction, 2 or-

For more information:

https://pubs.acs.org/doi/10.1021/acs.est.3c01146

Zycosan®

(pentosan polysulfate sodium injection)

250 mg/mL

For intramuscular use in horses only.

Brief Summary (For Full Prescribing Information, see package insert)

CAUTION: Federal law restricts this drug to use by or on the order of a licensed veterinarian.

DESCRIPTION: Zycosan contains pentosan polysulfate sodium, a semi-synthetic polysulfated xylan. It is a pale yellow to brownish yellow, clear, sterile solution.

INDICATION: For the control of clinical signs associated with osteoarthritis in horses.

CONTRAINDICATIONS: Horses with hypersensitivity to pentosan polysulfate sodium or any of the inactive ingredients in Zycosan should not receive Zycosan. Do not use Zycosan concurrently with other anticoagulant drugs. Do not use in horses with clotting disorders or within 24 hours of surgical procedures (see Warnings and Precautions).

WARNINGS AND PRECAUTIONS:

User Safety Warnings: Not for use in humans. Keep out of reach of children. Pentosan polysulfate sodium is a weak anticoagulant. Caution should be used when administering Zycosan if you are taking an anticoagulant. In case of accidental self-injection, seek immediate medical attention. If product comes into contact with skin, rinse skin thoroughly with water and seek medical attention if needed. To obtain a Safety Data Sheet (SDS), contact Dechra at (866) 933-2472.

Animal Safety Warnings and Precautions: Zycosan has been shown to prolong coagulation parameters up to 24 hours after injection, therefore caution should be used when administering this drug before or after strenuous activities (see Target Animal Safety). Due to the anticoagulant effects, this drug may exacerbate Exercise Induced Pulmonary Hemorrhage (EIPH).

gan systems that are primary targets of PFAS toxicity in humans.

“While the exposures that we found were generally low, we did see differences in concentration and composition for animals that live indoors versus outside,” said Scott Belcher, PhD, associate professor of biology at NC State and corresponding author of the work.

“The fact that some of the concentrations in dogs are similar to those in children reinforces the fact that dogs are important in-home sentinels for these contaminants,” Dr. Belcher said. “And the fact that PFAS is still present in animals that don't drink well water points to other sources of contamination within homes, such as household dust or food.”

The work appears in Environmental Science and Technology and was supported by the National Institute of Environmental Health Sciences and the North Carolina Policy Collaboratory. MeV

The concurrent use of NSAIDs with Zycosan has not been evaluated. Due to the anticoagulant effects of Zycosan and known anticoagulant effects of some NSAIDs, caution should be used if NSAIDs are concurrently administered. Horses concurrently treated with Zycosan and NSAIDs should be monitored for hemorrhage or other clinical signs of abnormal bleeding (e.g., petechiae, ecchymosis, or epistaxis). The safety of long-term repeat use of Zycosan has not been evaluated. Pigmentary changes in the retina (pigmentary maculopathy) have been reported in human patients following long-term oral use of pentosan polysulfate sodium. It is not known if a similar finding occurs in horses. The safe use of Zycosan has not been evaluated in breeding, pregnant, or lactating horses.

Other Warnings: Do not use in horses intended for human consumption.

ADVERSE REACTIONS:

Injection site reactions were the most frequently reported adverse reactions in the field study. Injection site reactions were associated with clinicopathology changes in some cases. Other adverse reactions reported in more than one horse were prolongation of coagulation parameters (activated partial thromboplastin time (aPTT) and prothrombin time (PT)), lethargy, behavior changes, and colic. To report suspected adverse events, for technical assistance or to obtain a copy of the Safety Data Sheet (SDS), contact Dechra at (866) 933-2472 . For additional information about adverse drug experience reporting for animal drugs, contact FDA at 1-888-FDA-VETS or online at http://www.fda.gov/reportanimalae.

STORAGE CONDITIONS: Store at room temperature 68-77°F (20-25°C), with excursions to 59-86°F (15-30°C).

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Dechra Veterinary Products

7015 College Boulevard, Suite 525

Overland Park, KS 66211 USA

Approved by FDA under NADA # 141-559

Zycosan is a trademark of Dechra Limited.

R 01 2023

Rock KD, Polera ME, Guillette TC, et al. Domestic dogs and horses as sentinels of per- and polyfluoroalkyl substance exposure and associated health biomarkers in Gray’s Creek North Carolina. Environmental Science & Technology

Breaking the Pain Cycle of Kissing Spine

By Emily Brooks

Dorsal spinous process impingement, or kissing spine, has long been a contributing factor in idiopathic lameness and has frustrated veterinarians and owners alike. As the equine veterinary community continues to try to understand the importance the role that the spine, pelvis and the sacroiliac joints play in soundness and longevity of sport and racehorses, the need to accurately diagnose and treat kissing spines has grown.

No matter your case population, chances are you have seen a horse with back pain if you are at all involved in lameness. Recently, I was involved in a case that took several years to hash out and showed the relevance of the pain cycle in other aspects of horse health.

An 11-year-old off the track Thoroughbred with a successful racing career became a sport horse project at the age of 4. The 17-hand gelding started a successful eventing career with professional 5-star rider in Lexington, Ky, when he began having issues with inconsistent performance, specifically in the cross-country phase.

The professional sold the horse to a young student and the pair was successful through novice/training level. When trying to move up a level, they began having the same performance issues as the more skilled rider. The owner brought the horse to me to try and show and

sell, despite the recent poor competition record and behavioral issues.

The gelding’s vices included neurotic weaving when stalled or tuned out alone, teeth grinding, during work and stall walking. The horse was in good body condition, but lacked a top line, or proper muscling over his back and hind quarters. I assumed this was due to lack of consistent work.

Based on the horse’s behavior, I recommended either having a gastroscopy performed or treating for gastric ulcers before I attempted to compete or sell him. The owner elected to treat for ulcers rather than spend the money for a gastroscopy. The horse was put on omeprazole daily for 3 weeks. It should be stated here that the owner is a boarded equine surgeon, so he prescribed the treatment. After 1 week of the oral omeprazole, the teeth grinding resolved, though the weaving and occasional stall walking persevered. I assumed that was just the horse’s learned behaviors. I increased turn out as much as possible, changed the feeding program to include alfalfa prior to exercise, and the horse’s performance in dressage remained very good. After several months of dressage training and only minor behavior issues under tack (spooking, occasional rearing, etc.), we began jumping.

The horse has a natural talent to jump but liked to get very close to the base of the fences, which was noted as his possible style. The gelding won his first 2 novice events with the lowest score of the entire show. I moved

The horse has a natural talent to jump but liked to get very close to the base of the fences, which was noted as his possible style.

A lateral radiograph of the dorsal spinous processes shows five sites of impingement

Teaching Points

Possibly one of the most important realizations of this case is that there is no obvious scale for overriding or impingement of dorsal spinous processes. Unlike recurrent laryngeal neuropathy or neurologic disease, there is not a scale that can be used. What radiographs look like versus what each individual horse can tolerate is so varied. Very successful competition and racehorses have worse radiographs than my horse and carry on without ever having back pain.

The important point is that each horse is different in the level of pain it experiences and can endure. Our jobs as riders and caretakers are to listen when they try to tell us something is wrong. Many horses are written off as poor performers, although in my experience inconsistency in performance in the absence of obvious lameness is the most telling sign of an underlying problem.

In this case the ulcers became the red flag much sooner than the chronic pain.

up to training level, winning 5 of 10, and placing in the top 3 of all shows entered. When preparing to move up to preliminary level, teeth grinding began, as well as hard spooking and refusal to move forward toward jumps, resulting in elimination.

Due to difficulty at this point being able to sell the horse, the owner transferred ownership to me to be rid of the expense. My experience has taught me that horses do not lose talent overnight. Poor performance or behavior changes are the only ways they can communicate pain in absence of an obvious lameness.

I opted to have a gastroscopy performed, and glandular and squamous ulceration was present. The horse was prescribed a treatment of omeprazole, sucralfate and alimend. The feeding plan was followed rigorously, with the omeprazole being administered when fasted, 30 minutes prior to feeding. He was given 30 days off while being treated for the ulcers and was to have a follow up gastroscopy prior to returning to work. On the repeat scope the ulcers had completely resolved. After discussion with the internist, it was decided to continue with a low dose of omeprazole for the first 30 days in work, and to treat with a full tube daily when traveling or competing.

When put back into work the horse’s performance was as it had been prior to the eliminations. Jumping was much better, and he appeared more willing to leave from an appropriate distance and stretch out over fences. Notably, with the return to rigorous training he had still never developed a topline as most eventers do, although his gluteal muscles were very well defined. He also had shown much sensitivity to grooming and girthing, though his “thin skinned” nature was often to blame.

At the time I was competing the horse, I was working at a different clinic. I brought him in to use for a model while teaching a radiography lab to the interns. As luck would have it, taking thoracic and lumbar spine views using a Canon wireless DR 14”x17” plate showed several areas of dorsal spinous process impingement.

I showed the findings to his previous owner but he did not think they looked bad enough to be clinically relevant. The only maintenance that the horse had ever had during his eventing career was occasional hock injections, which were described as beneficial by the previous rider. The horse had never been blocked for lameness to my knowledge.

We went on from there and had a stellar competition season, qualifying for the 2021 Training Level American Eventing Championships at the Kentucky Horse Park. He had been tolerating the training very well, and I continued the lower dose omeprazole in hopes of mitigating ulcers due to increased workload and stress.

The horse performed and scored very well in dressage, finishing fifth out of forty-five horse and within 4 points of first place. We went into cross country with every intention of jumping clear and fast. The first 18 fences were the most athletic and brave I have ever felt that horse jump. It was surely the most technical and difficult course I had ridden with him, as it should be during a championship. Fence 18 was a very large and wide-open oxer. He took the longer spot but jumped well out of stride. Upon landing we galloped well away, but I could tell the extra effort over the wide jump had jarred him slightly. Rounding the bend to the water complex he backed away from the gallop and refused to move forward. When I attempted to circle and re-approach, he reared, and I could tell he was done for the day.

After the show another gastroscopy was performed. Again, the squamous and glandular ulcers were back, despite the continued low dose omeprazole. This time we added misoprostil to the previously prescribed regiment and omitted the sucralfate, and again we gave him time off.

At this point in time, I began working for a different surgeon who is also boarded in sports medicine. I asked him to look at the horse with a fresh set of eyes.

Shutterstock/nelelena

He watched the horse jog and then palpated his legs and back. Baseline lameness was 0/5, though the horse seemed stiff behind on the straight line and circles. When the vet palpated the lumbar region, the horse responded by nearly buckling to the ground. His pain response was noted as marked. Review of the radiographs taken previously showed narrowing of the thoracic facets as well as the areas of impingement. This doctor recommended injecting the facets with Serapin and seeing if there was any improvement. He was doubtful that this would have any lasting effects, but wanted to prove that treatment would improve the pain prior to considering ostectomy. Use of a Pessoa training system or Equiband was also recommended to help strengthen the longissimus dorsi muscles and stabilize the back.

Resolution of palpable back pain in the lumbar region lasted for approximately 30 days. At that point I opted to have the surgery performed as a last-ditch effort to see if this horse could ever hold up to upper-level competition. We discussed at length the rehabilitation program post-surgery, as that has been determined to be as important as the surgery itself.

On Dec. 20, 2021 the horse had dorsal spinous process osteotomy on 5 sites deemed clinical on radiographs and palpation. Surgery was performed standing in stocks while a Detomidine CRI was given via intravenous route while under supervision of an anesthetist. Segments of the dorsal spinous processes were removed using radiograph guidance. Throughout the procedure the distance between dorsal spinous processes lengthened dramatically. Post operative instructions were to give 1 gram of phenylbutazone IV every 12 hours for 4 days and then decrease to 1 gram once per day for another week. Due to the known history of gastric ulceration a full dose of omeprazole was given as well. The horse was to be confined to a stall for 3 weeks, hand walk for 1 week, and then begin small paddock turn out for 2 weeks before increasing turn out size. The

horse would have a total of 4 months off work and then groundwork could begin, starting with long lining in an Equiband system. If exercise was tolerated well for1 month we could begin work under tack.

With my background in equine rehabilitation I decided to be very systematic in the approach to bringing him back. Once the sutures were removed at 14 days, I began doing carrot stretches, making the horse stretch left, right, and between his front legs, holding each stretch for at least 5 seconds. This proved helpful during grooming sessions while trying to keep him from being too pent-up during stall rest. After the prescribed rest we began work on the long line with the Equiband. I started with 15 minutes of walking with frequent transitions to halt and changes of direction. Care was taken to work each direction equally. After 2 weeks trot was integrated for a total of 10 minutes each direction maximum. Fatigue was always noted, and sessions would be shortened as needed. Immediate changes in the horse’s gait were noticed, including improvement in suspen-

Intra operative radiographs showing ostectomy and separation of the dorsal spinous processes

Dr. Sutter performing the ostectomy while the horse is in stocks. Dissected pieces of bone that were removed with a saw using radiograph guidance.

sion and swing of the hindquarters in both walk and trot.

It is very easy to quantify decline or improvement in racehorses since talent is based on time. Fractions are noted and catalogued, and race results are easily tracked. Sport horses don’t allow the same statistics because performance can be altered based on so many factors. It isn’t just the horse that finishes in the shortest amount of time, and dressage is a tediously subjective discipline. Much of what we know about performance is based on rider testimony.

Fortunately, my months of time spent with this horse allowed me to say with certainty that his overall attitude had improved, and he was moving with more ease and less tension than had ever been experienced.

After following the discharge instructions, I began riding at the 4-month post-op mark, with a conservative increase in time under tack and intensity of work. Throughout the rehab, I was constantly aware of the possibility of ulcers returning. It became clear that the horse had been dealing with chronic pain for years, and that had likely been the cause of the ulcers returning regardless of treatment and proven resolution. My hope was obviously that breaking the pain cycle would keep the ulcers from returning, and that upper-level competition could finally be achieved.

The summer was spent slowly increasing work and continuing with the Equiband twice per week. The surgeon came to check the horse’s progress after 6 months and was pleased with the response to surgery and lack

of any response to palpation of the back . The horse had also gained approximately 200 lbs after surgery, mostly in muscle and top line.

At the time I was putting this report together, this horse won his first competition back by 5 points, with no penalties in the jumping phases.

Another scope was done to find out if the ulcers remained resolved in the absence of back pain, and none were seen. His behavior has remained much calmer with no bruxism or weaving. We continue to manage him with free choice alfalfa and omeprazole during times of increased travel or stress. I am hopeful, I can compete him at the 1-star level next spring. We plan to evaluate his soundness and scope for ulcers every 6 months. MeV

About the Author

Emily Brooks has worked as an equine veterinary technician since 2007, starting her career at Rood and Riddle Equine Hospital. Her interest quickly focused on advanced diagnostic imaging modalities and there she ran high field MRI, CT, and performed musculoskeletal ultrasound for lameness exams and surgery. Emily has traveled to the Equine Veterinary Medical Center in Doha, Qatar to help set up their imaging center in 2018 and now works at Kentucky Equine Hospital as the head imaging technician in Simpsonville, KY. She also runs a sport horse rehabilitation facility and trains and shows dressage horses and eventers.

The horse responded to surgery and rehab, gained 200 lbs, mostly in muscle and top line. By the time of this report, he won his first competition by 5 points with no penalties in the jumping phase.

Assessing Emotions in Wild Horses

A framework for assessing the mental and psychological wellbeing of wild animals has been developed by UTS Chancellor’s Postdoctoral Research Fellow Andrea Harvey, DVM, an animal welfare scientist in the University of Technology Sydney.

The significance of the study lies in its potential to revolutionize conservation efforts. Instead of focusing solely on population numbers and reproductive success, the research explores the quality of life experienced by wild animals.

This shift in perspective could provide crucial early warning signals about species challenges and population declines, leading to more effective conservation strategies.

“While research on the welfare of domestic and farm animals has been considerable, including indicators of emotional states such as stress, pain and fear, my aim is to bridge the gap by examining the individual lives, feelings and mental experiences of wild animals,” Dr. Harvey said.

“A deeper understanding of the wellbeing of wild animal populations can not only enhance conservation efforts, but also provide an indication of the state of the natural environment and its recognized links to human health and wellbeing.”

The study, which was part of Andrea’s PhD research at the UTS Centre for Compassionate Conservation, focuses on brumbies—free-roaming wild horses—from Australia’s alpine regions, however the framework is widely applicable for evaluating many wildlife species.

Dr. Harvey chose brumbies as horse welfare has been studied in domestic environments, providing a bridge to wild animals.

Her comprehensive conceptual framework, called the 10 Stage Protocol, includes physical and behavioral indicators for both negative and positive mental experiences in wild animals.

“If you have a dog, you know their usual routine, what they like, and how

they behave in certain circumstances. You know if they’re happy, sad or distressed, so this research is shifting that understanding to wild animals.”

“We can never be certain what’s going through an animal’s mind and exactly what they’re feeling. It’s also an area that scientists have traditionally shied away from. However, we know mental experiences arise from physical states, and we can directly measure these states.

“Nutrition, the physical environment, health, and behavioral interactions all provide clues to the mental experience of animals. This includes negative states such as thirst, hunger, heat and cold discomfort, pain, fatigue, anxiety and fear and positive ones such as satiety, exercising agency, physical vitality and positive social interactions.”

This holistic approach brings together different areas of scientific knowledge, including neuroscience, behavior, and neuroethology—the study of the neural basis of an animal’s natural behavior—to interpret the data collected and gain insights into wellbeing.

“Welfare assessments need to be part of all wildlife monitoring, and ultimately all environmental policy decision making, which needs to take into account not just individual species, but also interactions between different species, and their ecosystems.”

MeV

Harvey AM, Beausoleil NJ, Ramp D, et al. Mental experiences in wild animals: scientifically validating measurable welfare Indicators in free-roaming horses. Animals 2023;13(9):1507 DOI: 10.3390/ani13091507