Misoprostol for Gastric Ulcers in Horses

Many horse owners automatically think of omeprazole when gastric ulcers occur, and they aren’t wrong to do so. Several studies show that omeprazole heals ulcers, particularly those in the squamous region of the stomach, by decreasing the production of gastric acid. Other treatment options include sucralfate, an agent that binds to the damaged tissues to promote healing, and a medication called misoprostol.

“Misoprostol reportedly works by inhibiting gastric acid production and the digestive enzyme pepsin, enhancing the resilience of the stomach wall to injury through its anti-inflammatory properties, and increasing blood flow to the stomach lining,” said Catherine Whitehouse, M.S., a nutrition advisor for Kentucky Equine Research.

One recent study^* pointed out that misoprostol was more effective than a combination of omeprazole and sucralfate for horses with ulcers in the glandular region of the stomach.

This study also emphasized that some horses have a higher risk of developing gastric ulcers than others. This includes horses that have recently been administered a nonsteroidal anti-inflammatory drug (NSAID) such as phenylbutazone (bute), those that underwent colic surgery, or horses that recently had feed withheld.

“Phenylbutazone and other NSAIDs can cause ulceration in the stomach as well as the right dorsal colon, initiating a bout of colic and diarrhea,” Whitehouse added.

Regardless of what drug protocol is used to heal gastric lesions, for many ulcer-prone horses, the next important management step is selecting an effective antiulcer supplement to prevent recurrence. Choose a product that has been researched thoroughly by a reputable, established company. Kentucky Equine Research has formulated several products for gastric and hindgut health.

For horses that require periodic dosing with NSAIDs, hindgut support is often warranted. Appropriate research-proven supplements include RiteTrac and EquiShure.

 ^*Lopp, C.T., A.M. McCoy, D. Boothe, et al. 2019. Single-dose pharmacokinetics of orally and rectally administered misoprostol in adult horses. American Journal of Veterinary Research 80:1026-1033.