Effect of a Histamine H2 Type Receptor Antagonist (WY 45, 727) on the Healing of Gastric Ulcers in Ponies

Using video gastroscopy, the efficacy of a Histamine-H2 type receptor antagonist (WY 45, 727) was investigated in young ponies with spontaneous and experimentally induced gastric ulcers. Oral administration of WY 45, 727 at 2 mg/kg and 10 mg/kg of body weight every 12 hours for 14 days resulted in complete healing of spontaneous gastric ulcers in the non-glandular portion of the stomach in 2/5 (40%) and 3/4 (75%) of the ponies, respectively, compared (P < 0.05) to 0/5 (0%) placebo-treated ponies. After intramuscular administration of flunixin meglumine at 1.5 mg/kg body weight every 8 hours for 6 days, 9/18 ponies had ulcers in the non-glandular portion of the stomach. Oral administration of WY 45, 727 at 10 mg/kg body weight every 12 hours for 14 days resulted in complete healing of the non-glandular gastric ulcers in 3/4 (75%) compared with (P < 0.05) 1/5 (20%) placebo-treated ponies. This study indicates that 1) the occurrence of subclinical ulcers may be common in young ponies; 2) flunixin meglumine at 1.5 mg/kg intramuscularly every 8 hours for 6 days may result in ulcers of the non-glandular stomach in ponies; and 3) WY 45, 727, a histaminergic H2 type receptor antagonist could be of value in the therapeutic management of ulcers in the non-glandular stomach of foals and adult horses.