The effect of porcine hydrolysed collagen on gastric ulcer scores, gastric juice pH, gastrin and amino acid concentrations in horses

Summary Gastric ulcers are common in horses. The purpose of this study was to test the effect of porcine hydrolysed collagen (PHC) on gastric ulcer scores and gastric juice pH in horses. We hypothesise that PHC‐administration will result in improved gastric lesion scores and act synergistically with omeprazole to improve treatment efficacy. Thoroughbred horses (n = 10) were studied in a 2‐period, 2‐treatment crossover design, where the PHC (45 g) was administered twice daily. Horses were treated for 56 days. Gastroscopy was performed and gastric juice pH measured on Days 0, 14, 28, 42, 49 and 56. Nonglandular gastric ulcer number (NGN) and severity (NGS) and glandular ulcer number (GN) and glandular severity (GS) scores were assigned by an investigator masked to treatment and serum gastrin and amino acid concentrations. By Day 42, 2 weeks after discontinuing omeprazole treatment, NGN and NGS scores returned to pretreatment values and serum gastrin was higher when compared to values measured on Day 28. By Day 49, after the feed‐deprivation period, NGN and NGS were similar to pretreatment values. By Day 56, mean NGN score was significantly lower in PHC‐treated horses, compared to controls. Mean gastric juice pH significantly increased in both groups on Day 28 and the pH was significantly (P = 0.0127) higher in the PHC‐treated horses. Serum amino acid concentrations were not significantly different 2 h after feeding PHC and hydroxyproline was not detected. Serum gastrin concentration did not increase 2 h after feeding in the PHC‐fed horses. The PHC fed to horses enhanced the effects of omeprazole on increased gastric juice pH, inhibited gastrin secretion after feeding and resulted in fewer nonglandular ulcers after long‐term feeding (56 days) in stall‐confined horses undergoing intermittent feeding.