Which Horse Has Stomach Ulcers?

Signs of ulcers in horses may be more subtle than you think.

From Corporate Partner Boehringer Ingelheim

Stomach ulcers can not be seen by the naked eye. So how do you know they are there? Photo from Boehringer Ingelheim

Horse owners understand the hard work that goes into the gleam of a shiny coat – regular grooming, good nutrition and so much more – but if the hair coat starts to look poor, do the same horse owners consider stomach ulcers as a possible cause?1 Unfortunately, signs of ulcers in horses aren’t always that predictive.

Consider these two horses – guess which one has stomach ulcers. Both? Neither? How would you know?

“You never know what a shiny coat could be hiding,” says Hoyt Cheramie, DVM, MS, DACVS, Senior Equine Professional Service Veterinarian, Boehringer Ingelheim. “While common signs such as a poor hair coat, decreased appetite or poor body condition may be telling, picking up on subtle behavior or performance changes can also point to equine stomach ulcers.”  

Cheramie explains that clinical signs of equine gastric ulcer syndrome (EGUS) are not pathognomonic, meaning not very highly associated with the disease. Some signs of EGUS, such as behavioral issues or poor performance,1 can be so common that they are often just ignored or blamed on something else.

Risk Factors

EGUS, caused by rising stomach acid levels, isn’t limited to show horses and race horses. The horse left at home is still at risk for stomach ulcers, and 11 percent of horses that are rarely competed and predominantly used in their home environment have ulcers.1,2 Foals and broodmares are at risk, too. The presence of ulcers in foals has been reported as ranging between 25 percent and 51 percent.3,4 One study showed that more than 70 percent of broodmares had ulcers.5

“When you think of EGUS risk factors, consider how you feed and manage your horse,” Cheramie says. “The horse is meant to graze almost continuously. Common feeding and housing programs, which include grain concentrates and infrequent dry roughage meals, often result in the horse's stomach being empty and/or producing excess acid. Add in stress, and it is likely your horse will develop ulcers.”

Additionally, Cheramie urges horse owners to look beyond the obvious risk factors. Studies have shown that playing a radio or even increasing a horse’s number of caretakers can contribute to ulcers.6,7

Diagnosis and Treatment

Signs of equine stomach ulcers may be subtle and the risks may be great, but you can’t see them with the naked eye. For diagnosis, your veterinarian may recommend gastroscopy, the only way to definitively diagnose equine stomach ulcers and determine severity and location.

Gastroscopy is an easily performed and well-tolerated procedure where your veterinarian will pass a long tube with a camera at the end through the nose and esophagus and into the stomach.

If ulcers are found during the procedure, your veterinarian may recommend a course of treatment with Gastrogard® (omeprazole), the only proven and FDA-approved product for the treatment of equine stomach ulcers. Additional medications may be recommended based on ulcer severity and location.

Management and Prevention

Given the reported incidence of ulcers in horses, and the varying circumstances that can contribute to ulcers, it may be beneficial to implement protocols to aid in prevention. Ulcergard® (omeprazole) is a proven product for the prevention of stomach ulcers in horses. Cheramie also suggests providing continuous access to roughage through grazing or hay-restrictive feeders or nets and feeding grain divided into multiple small meals daily.

“Work with your veterinarian to make management changes,” Cheramie says. “An ounce of prevention is worth a pound of cure, and that saying holds true when it comes to equine stomach ulcers.”

Ulcer signs may go beyond a poor hair coat, and they may be subtle. Make sure you pay attention to your horse’s health and consider even the less obvious risk factors. Talk to your veterinarian about diagnosing, treating and preventing equine stomach ulcers.


IMPORTANT SAFETY INFORMATION: The safety of GASTROGARD paste has not been determined in pregnant or lactating mares. For use in horses and foals 4 weeks of age and older.

Keep this and all drugs out of the reach of children. In case of ingestion, contact a physician.

ULCERGARD can be used in horses that weigh at least 600 pounds. Safety in pregnant mares has not been determined. Not for use in humans. Keep this and all medications out of the reach of children. In case of ingestion, contact a physician.

About Boehringer Ingelheim Animal Health
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Innovative medicines for people and animals have for more than 130 years been what the research-driven pharmaceutical company Boehringer Ingelheim stands for. Boehringer Ingelheim is one of the industry’s top 20 pharmaceutical companies and to this day remains family-owned. Day by day, some 50,000 employees create value through innovation for the three business areas human pharmaceuticals, animal health and biopharmaceutical contract manufacturing. In 2016, Boehringer Ingelheim achieved net sales of around 15.9 billion euros. With more than three billion euros, R&D expenditure corresponds to 19.6 per cent of net sales.

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GASTROGARD and ULCERGARD are Merial products. Merial is now part of Boehringer Ingelheim.
®GASTROGARD and ULCERGARD are registered trademarks of Merial. ©2018 Merial, Inc., Duluth, GA. All rights reserved. EQU-0622-EGUS0618.


1Sykes BW, Hewetson M, et al. European College of Equine Internal Medicine Consensus Statement – Equine Gastric Ulcer Syndrome in Adult Horses. J Vet Intern Med. 2015;29:1288-1299.

2McClure SR, Carithers DS, Gross SJ, Murray MJ. Gastric ulcer development in horses in a simulated show or training environment. J Am Vet Med Assoc. 2005;227(5):775-777.

3Wilson JH. Gastric and duodenal ulcers in foals: a retrospective study, in Proceedings, 2nd Equine Colic Res Symp. 1986;126-129.

4Murray MJ, Hart J, Parker GA. Equine gastric ulcer syndrome: endoscopic survey of asymptomatic foals. AAEP Proceedings. 1987;33:769-776.

5Ie Jeune SS, Nieto JE, et al. Prevalence of gastric ulcers in Thoroughbred broodmares in pasture: a preliminary report. Vet J. 2009;181(3):251-255.

6Lester GD, Robertson I, Secombe C. Rural Industries Research and Development Corporation (Australia) 2008. Risk factors for gastric ulceration in thoroughbred racehorses. Rural Research and Development Corporation, Barton, A.C.T.

7Mönki J, Hewetson M, Virtala A‐MK Risk Factors for Equine Gastric Glandular Disease: A Case‐Control Study in a Finnish Referral Hospital Population. J Vet Intern Med. 2016;30(4):1270–1275.


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