Effects of dietary oils on the development of gastric ulcers in mares.

Objective: To assess antiulcerogenic properties of 3 dietary oils.
Animals: 8 healthy adult mares.
Procedure: A protocol to induce gastric ulcers was used and included 240 mL of water plus corn oil, refined rice bran oil, or crude rice bran oil administered each day for 6 weeks according to a 4 x 4 Latin square randomized crossover design with 5-week washout intervals. A 7-day alternating feed deprivation period was included between weeks 5 and 6. Omeprazole was administered daily for the last 14 days of each washout interval. Endoscopic examinations of the stomach were performed at 0, 5, and 6 weeks, and the number (0 to 4 scale) and severity (0 to 5 scale) of ulcers were scored. Gastric fluid was collected at 0 and 5 weeks.
Results: Median body weight significantly increased by 29 kg (range, 10 to 50 kg). Mean +/- SE gastric fluid pH significantly decreased from 4.9 +/- 0.4 to 3.1 +/- 0.3 over 5 weeks, and total volatile fatty acid concentration significantly decreased over time. Mean +/- SE severity of nonglandular ulcers significantly increased from 0.4 +/- 0.1 to 1.2 +/- 0.2 over 5 weeks. Nonglandular ulcers significantly increased in number (mean +/- SE, 1.3 +/- 0.2 to 3.0 +/- 0.2) and severity (mean +/- SE, 1.2 +/- 0.2 to 2.6 +/- 0.2) during the 7-day alternating feed deprivation period. No effects of treatment were detected.
Conclusions and Clinical Relevance: In this model dietary oils did not prevent gastric ulcers from forming in the nonglandular portion of the stomach of horses.