Research from Louisiana State University suggests that a new supplement may help reduce the recurrence of gastric ulcers among horses that have undergone successful treatment with omeprazole.

Estimated to affect 60 to 90 percent of horses, gastric ulcers are erosions of the stomach lining caused by excessive acid production. Competition, intense training, transport and other stressors increase a horse’s risk for ulcers, which often lead to weight loss, poor performance, a sour attitude and colic. Diagnosis is usually made through endoscopic0 examination.

A four-week regimen of the omeprazole (sold under the brand name GastroGard), which reduces the production of stomach acid, usually resolves gastric ulcers. But afterward some horses experience a recurrence because their acid secretions return to pretreatment levels or even higher, a phenomenon known as rebound acid hypersecretion (RAH). “Omeprazole treatment leads to a decrease in acid secretion and, as a result, G-cells of the stomach release gastrin—a hormone that stimulates acid secretion—in the blood,” explains Frank Andrews, DVM, MS, DACVIM. “With drug cessation, [acid production increases] leading to acid-related heartburn, acid regurgitation or dyspepsia. All this can lead to recurrence of ulcers in horses.”

To determine whether SmartGut Ultra, a supplement containing a proprietary blend of sea buckthorn, L-glutamine, aloe vera, pectin and lecithin known as GastrAvert, can mitigate RAH, Andrews’ team of LSU researchers selected eight horses with various levels of gastric ulcer severity. Their study was performed over two 42-day periods (a two-period, two-treatment cross-over design). For the first period, half of the horses received SmartGut Ultra and half received no treatment; for the second period, the treatment/nontreatment groups were swapped so each horse could serve as his own control.

For the first 14 days of the study, all the horses were given omeprazole. Next, the omeprazole was halted for two weeks. For seven days after that, the horses were placed on a restricted diet to stimulate ulcer formation. Then, for the final seven days of the study, the normal ration was resumed. On the first and last days of the study, as well as three times during it, Andrews’ team examined each horse’s stomach lining with an endoscope to identify and score nonglandular ulcers and measured the pH of their gastric juices.

The data showed that at the beginning of the study ulcer scores were similar, but immediately after omeprazole treatment they markedly decreased to the same degree in both groups. However, by the fourth and fifth week of the study, when the omeprazole was discontinued and after the feed deprivation period, horses fed the supplement had significantly fewer and less severe ulcers than did the control horses.

Based on this research, Andrews advises starting horses on the SmartGut Ultra supplement when they are treated for ulcers, then continuing to feed it once treatment has ended.

Reference: “The effect of a supplement (SmartGut® Ultra) on the non-glandular gastric ulcer scores and gastric juice pH,” American Association of Equine Practitioners 60th Annual Convention Proceedings, December 2014.

This article first appeared in EQUUS issue #450, March 2015.