Efficacy of a Combination of Apolectol, Live Yeast (Saccharomyces cerevisiae [CNCM I-1077]), and Magnesium Hydroxide in the Management of Equine Gastric Ulcer Syndrome in Thoroughbred Racehorses: A Blinded, Randomized, Placebo-Controlled Clinical Trial

To date, prevention of equine gastric ulcer syndrome (EGUS) has relied on management changes or pharmaceutical agents. The identification of an alternative means of prevention would be useful. Therefore, the objective of this study was to evaluate the combination of Apolectol, a live yeast (Saccharomyces cerevisiae [CNCM I-1077]), and magnesium hydroxide for the prevention of development of, or exacerbation of existing, EGUS in Thoroughbred racehorses. Twenty-four Thoroughbred racehorses without significant gastric ulceration (grade, ≤2 of 4) were identified on gastroscopy. Treated horses received 95 g Apolectol, 2 g S. cerevisiae, and 20 g magnesium hydroxide 1-4 hours before exercise. Control horses received 95 g of a feed pellet as a placebo. Gastroscopy was repeated at 24-27 days. There was no change in squamous (P = .45) or glandular (P = 1.0) ulcer grade over time in horses in the treatment group. In the placebo group, ulcer grade increased in both the squamous (P = .04) and glandular (P = .19) mucosa but only reached significance in the squamous mucosa group. Worsening of the ulcer grade was more likely in the placebo group in the glandular (P = .04) but not in squamous (P = .10) mucosa. The combination studied may be an effective prophylactic against EGUS development or exacerbation.