One of the most misdiagnosed and mistreated conditions in equine medicine is equine gastric ulcer syndrome, or EGUS. This is curious, given the advancements in diagnostic technology and veterinary medicine overall in recent years. Still, a definitive diagnosis of EGUS in any given horse often remains elusive until the animal’s health has significantly deteriorated. 

“Gastritis” is the general term used to describe inflammation and/or irritation of the stomach lining, but this is actually a tangential condition caused by the underlying disease process. Gastric ulcers are highly prevalent in horses, and result in decreased performance and loss of revenue. The prevalence of EGUS in domesticated horses is high, with its prevalence in performance horses (such as Thoroughbreds in race training) running as high as 70 to 94%.¹

How Do Horses Get GI Ulcers?

The horse’s stomach lining consists of two different tissue types:

• The Squamous mucosa (this includes the top half of the stomach)
• The Glandular mucosa (this includes the bottom half of the stomach)

Ulcers can occur in either of these locations, but they are much more common in the squamous mucosa, which is similar in structure to the lining of the esophagus. While the glandular mucosa contains acid-producing cells, most equine gastric ulcers affect the squamous mucosa.² Exposure to excess acid is the principal mechanism responsible for squamous mucosal ulceration.

Ulcers in horses are sometimes accompanied by hindgut or colonic ulcers. While gastric ulcers are found in the stomach, colonic ulcers are lesions that occur in the hindgut. Horses are known as “hindgut fermenters”, which means that the horse ferments forage in its colon to create Volatile Fatty Acids which produce the majority of a horse’s energy. The risk for colonic ulcers is even greater in performance horses and those that are already suffering from gastric ulcers.² As with gastric ulcers, colonic ulcers occur when the mucosal lining of the affected area is damaged. 

Clinical Signs of Gastric Ulcers

The clinical signs of EGUS in horses vary, and typically include anorexia and chronic or intermittent colic.¹ “Many horses with endoscopic evidence of disease may appear to be clinically normal or have vague signs that include decreased consumption of concentrates, postprandial episodes of colic, poor performance or failure to train up to expectations, poor quality hair coat, and decreased condition or failure to thrive.”³ Diarrhea is not typically associated with gastric ulceration in horses, but can occur in cases of colonic ulcers.²

Although a diagnosis of EGUS can be suspected based upon clinical signs and response to treatment, the only current method of confirmation is via gastroscopy, which can easily be performed in the standing horse with mild sedation after a 12-18 hour fast.

Treatment of Equine Gastric Ulcer Syndrome

Since acid is the essential culprit in the case of squamous ulcer disease, most anti-ulcer therapy centers on decreasing gastric acid.¹ The principal therapeutic options for ulcer treatment include H² antagonists such as cimetidine, ranitidine and famotidine), proton pump inhibitors (or PPIs) such as omeprazole, pantoprazole and esomeprazole), and the mucosal adherent sucralfate.

Sucralfate has been widely used in treating ulcers affecting the glandular part of the stomach in horses. 

Sucralfate is contraindicated in patients with known hypersensitivity to it, and has several drug interaction warnings. Because it may cause constipation, it should be used with caution in animals in which decreased GI transit times might be deleterious.³ Otherwise, no contraindications nor serious adverse effects have been reported.

Where to buy Sucralfate

Sucralfate is available in the U.S. through pharmaceutical manufacturers and through veterinary custom compounding companies. 

Please consult your veterinarian prior to beginning any treatment regimen.

FOR RX ONLY: A valid prescription from a licensed veterinarian is required for dispensing this medication.

¹McClure SR, Glickman LT, Glickman NW. Prevalence of gastric ulcers in show horses. Journal of the American Veterinary Medical Association. 1999 Oct;215(8):1130-1133.

²Nadeau, J., et. al. Evaluation of diet as a cause of gastric ulcers in horses. AJVR, Vol 61, No. 7, July 2000.

³Murray MJ. Gastric ulceration in horses: 91 cases (1987-1990). Journal of the American Veterinary Medical Association. 1992 Jul;201(1):117-120.

⁵Videla R, Andrews FM. New perspectives in equine gastric ulcer syndrome. Vet Clin North Am Equine Pract. 2009;25(2):283-301.