Two articles on the use of omeprazole paste (GastroGard from Merial) in racehorses were published in the May 15 edition of the Journal of the American Veterinary Medical Association (JAVMA). The first study looked at using omeprazole paste to prevent gastric ulcers in horses entering race training. The second study looked at the efficacy of omeprazole paste to prevent the recurrence of gastric ulcers in horses in race training.

In the first study, the researchers, led by Scott R. McClure, DVM, PhD, Dipl. ACVS, of Iowa State University College of Veterinary Medicine, reported that “Omeprazole administered at a dosage of 1 mg/kg every 24 hours for 28 days was effective for prevention of gastric ulcers in horses starting race training.” An interesting note in that study was that only four of 39 horses (10%) treated with a sham product (containing no omeprazole) were ulcer-free compared to 31 of 38 horses treated with omeprazole (82%) that were ulcer-free.

In the second study that included many of the same researchers and which again was headed by McClure, they found that “Omeprazole oral paste administered at a dosage of 1 mg/kg every 24 hours for 28 days was effective for prevention of recurrence of gastric ulcers in horses in race training.”

In reporting this study in JAVMA, the researchers noted that, “Sham-dose-treated horses and horses receiving 0.5 mg or omeprazole/kg had significantly higher ulcer scores (more and/or more sever ulcers) than did horses receiving 1 mg of omeprazole/kg.” They also reported a “significant difference” in how many horses remained ulcer-free comparing omeprazole-treated and sham-treated groups. In the treated group, 38/48 horses (79%) remained ulcer-free, and only 7/44 (16%) of the untreated group remained ulcer-free