Horse supplements are a funny thing—equestrians spend millions of dollars each year on them, but only a small percentage are backed with scientific studies showing their efficacy. So recently, a team of researchers set out to put some science behind one digestive health supplement.

At the 2014 American Association of Equine Practitioners Convention, held Dec. 6-10 in Salt Lake City, Utah, Nicola Kerbyson, BVMS, Cert. AVP (EM), MRCVS, presented the results of a study evaluating one supplement’s effects on gastric ulcer severity compared to the current gold-standard treatment: omeprazole. Kerbyson is a PhD student at the University of Glasgow, in Scotland.

Kerbyson said omeprazole has been well-studied up to 56 days of administration (where its reported efficacy is very good, she said), but noted that many horses are treated for much longer periods. She also noted that there’s been recent interest from consumers regarding supplements for managing gastric ulcers, especially since corn oil has been shown to reduce gastric acid output.

So Kerbyson and colleagues carried out a study comparing the effects of SUCCEED—a commercially available dietary supplement containing polar lipids (oat oil), soluble fiber (β-glucans), and amino acids (L-glutamine and L-threonine) marketed as a digestive supplement to assist the healing of gastric ulcers—and omeprazole on the development and treatment of squamous gastric ulcer (those in the stomach’s nonglandular area) development in Thoroughbred racehorses.

The team began with 67 horses either in training or actively racing diagnosed with squamous ulcers rated Grade 1 or