EFFECT OF RANITIDINE ON HEALING OF EXPERIMENTALLY-INDUCED GASTRIC-ULCERS IN PONIES

Thirty young ponies were examined endoscopically for evidence of gastr ic ulceration. Seven ponies had noninduced gastric ulcers present at t he initial examination and were eliminated from the study. In an attem pt to induce gastric ulcers experimentally, flunixin meglumine (1.1 mg /kg of body weight, im, q 8 h) was administered for 7 days to the 23 p onies with endoscopically normal gastric mucosa. During the 7 days of flunixin administration, 11 ponies developed gastric ulcers that were appropriate for study. The 11 ponies were randomly allotted to 2 group s. Group-A (n = 5) and group-B (n = 6) ponies received ranitidine (4.4 mg/kg, PO, q 8 h) and corn syrup, respectively, until ulcers healed o r for a maximum of 40 days. General anesthesia was induced every 3 to 5 days for visual evaluation of ulcer healing by use of a video endosc ope. The earliest complete healing of gastric lesions observed in a co rn syrup-treated pony was at 17 days. At 40 days, 3 of 5 and 3 of 6 po nies of the ranitidine and com syrup-treated groups, respectively, had healed ulcers. Results of this study indicate that: noninduced gastri c ulcers may be common in young ponies, flunixin meglumine may be effe ctive in inducing gastric ulcers for gastric healing studies in young ponies, and ranitidine (4.4 mg/kg, q 8 h) is not significantly effecti ve in accelerating healing of experimentally induced gastric ulcers in ponies under conditions of this study.