Treatment of gastric ulcers in horses with histamine type 2 receptor antagonists.

Of 55 horses treated with histamine type 2 (H2) receptor antagonists for gastric ulcers, 32 were examined by gastroendoscopy before and after treatment. Distribution and severity of lesions in the squamous fundus (sf), margo plicatus (mp), glandular fundus (gf), lesser curvature (lc) and cardia (car) were recorded. Severity of the lesions was scored 0-4 (0 = no lesions, 4 = most severe). On initial examination, lesions were most frequently observed at the mp (28/32) and least frequently observed in the gf (5/32). There was endoscopic confirmation of improvement in lesion scores in each region, although the magnitude of improvement and duration of treatment required to affect total healing varied by region. The mean (+/-sd) changes in lesion scores in each region of the stomach after treatment were: -1.92 +/- 1.43 (sf), -2.27 +/- 0.98 (mp), -1.60 +/- 0.80 (gf), -1.20 +/- 1.81 (lc), and -2.00 +/- 1.85 (car). Clinical improvement was noted in 54 of 55 animals, as indicated by decreased frequency of colic episodes, weight gains, and improved appetite. It was concluded that H2 antagonists are an effective treatment of gastric ulcers in horses, as determined by endoscopic and clinical improvement.