Study Shows Omeprazole Prevents Ulcers in Young Racehorses

Gastric ulcers are an occupational hazard for Thoroughbreds, with up to 90% of all active racehorses currently affected. Omeprazole paste is currently licensed for treating and preventing gastric ulcer recurrence in horses, but until now researchers have not studied its efficacy in preventing ulcers from forming in young Thoroughbred racehorses.

"One of the factors thought to contribute to the development of gastric ulcers in racehorses is housing," said Yoshiro Endo, DVM, from the Japan Racing Association's Hidaka Training and Research Center in Urakawa, Hokkaido.

Racehorses worldwide are frequently housed individually in stalls or small paddocks except when taken out for training. Lack of pasture access, in addition to intensity and/or duration of physical exercise, is one reason scientists believe adult racehorses commonly suffer from ulcers.

Endo explained, "It is not currently known what the prevalence of gastric ulcers is in 2-year-old Thoroughbreds that are just starting their careers and haven't been housed under the same stressful, ulcer-inducing conditions as older racehorses."

In their study, Endo and colleagues endoscopically examined the stomachs of 85 young Thoroughbreds three months after starting training and being housed individually in stalls or paddocks. Only 23 (27%) had gastric ulcers at that time, and most ulcers were mild (score of less than two on a three-point scale, with three being the most severe).

They subsequently divided the 62 horses that did not have gastric ulcers into two groups: one group received omeprazole (sold under the brand name GastroGard) at a rate of 1 mg/kg body weight/day) and the other remained untreated. After 28 days only one horse in the treatment group had an ulcer whereas 12 (38.7%) of the untreated horses had ulcers (grades 1 and 2).

"This study proves that ... GastroGard is highly effective in preventing gastric ulcers, which can contribute to poor performance, in 2-year-old racehorses," summarized Endo.

He added, "Omeprazole paste appears to be more effective in preventing ulcers in young horses compared to older racehorses considering that all ulcers documented in this study were only very mild."

The study, "Efficacy of omeprazole paste in the prevention of gastric ulcers in 2-years-old Thoroughbreds," is scheduled to be published in an upcoming edition of The Journal of Veterinary Medical Science. The full-length manuscript is available for free through PubMed.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.