Effect of a pelleted supplement fed during and after omeprazole treatment on nonglandular gastric ulcer scores and gastric juice pH in horses

Gastric ulcers are common in horses. The purpose of this study was to test the effect of a commercially available supplement, SmartGut((R)) Ultra pellets (SmGU) on gastric ulcer scores and gastric juice pH after omeprazole treatment in stall-confined horses. Eight Thoroughbred horses were studied in a 2-period, 2-treatment crossover design, where the SmGU (40g, twice daily) was mixed in grain feed. Horses were stall-confined and treated with the supplement or control for 6weeks, consisting of 2weeks (Days 1-14) omeprazole treatment, 2weeks (Days 14-28) following discontinuation of omeprazole treatment, oneweek (Days 28-35) alternating feed deprivation to induce or worsen existing ulcers and a oneweek (Days 35-42) recovery period. Gastroscopy was performed and gastric juice pH measured on Days 0, 14, 28, 35 and 42. Gastric ulcer lesion number (NGN) and severity (NGS) scores were assigned to each horse by an investigator (F.M.A.) masked to treatment. On Day 0 before treatment, mean NGN and NGS scores and gastric juice pH were not different (P>0.05) between treatment groups. By Day 14, mean NGN and NGS scores decreased (P<0.05) in both treatment groups. By Days 28 and 35, mean NGN score significantly increased in the untreated control horses but not the SmGU-treated horses. By Day 42, mean NGN and NGS scores were not different in either group and were significantly lower than Day 0. Mean gastric juice pH was higher in both groups on Day 14 as a result of omeprazole treatment when compared with other days. SmartGut((R)) Ultra supplement added to the feed prevented the worsening of gastric ulcer number 2weeks after omeprazole treatment, without altering the gastric juice pH. Supplementation with SmGU might aid in protection of the nonglandular stomach from recurrence of ulcers after omeprazole treatment in stall-confined horses undergoing intermittent feeding.