Effects of a dietary supplement on gastric ulcer number and severity in exercising horses

This study evaluated the effect of a dietary supplement on the treatment of equine gastric ulcer syndrome (EGUS). Gastroscopy was performed on university riding horses of mixed breeds at two locations and only horses exhibiting gastric ulcers were selected to participate in this study (location A, n = 13; location B, n = 15). Gastric ulcer severity was assessed using two different methods depending on location before treatment (Pre). After gastroscopy, horses were fed the supplement in addition to their regular diet for 44 d (14-d adaptation period followed by 30-d feeding period). All horses were subjected to gastroscopy again at the end of the feeding period (Post) to evaluate changes in gastric lesions. Statistical analysis was performed using SAS. Individual horses were the experimental unit with dependent variables including severity and number of gastric ulcers. At location A, dependent variable included severity of gastric lesions with fixed effects of time (Pre and Post) and location (stall or pasture). For location B, dependent variables included severity and number of gastric lesions with fixed effects of time. Severity of gastric ulcers decreased at both locations in horses following the feeding period. Gastric lesion scores decreased from 2.2990 to 1.3760 (P = 0.0015) at location A and gastric lesion severity from 3.8000 to 2.5667 (P = 0.0322) at location B. No differences were found in gastric lesion scores at location A between horses housed in stalls or pastures (1.8750 and 1.8000; P = 0.7783). The number of gastric ulcers observed at location B were similar Pre and Post treatment (3.4667 and 3.5333; P = 0.8363). There were no changes in body condition score (P ≥ 0.2607), BW (P ≥ 0.4551), or behavior at either location. Results suggest that oral supplementation may decrease severity of gastric ulcers in horses participating in university riding programs.