Cross-sectional study of gastric ulcers of the squamous mucosa in thoroughbred racehorses.

Although gastric ulcers have been identified relatively frequently in racing Thoroughbreds, there have been no large scale studies to determine their effect on health and performance. Two hundred and two Thoroughbred horses in active race training were selected by the attending veterinarians for gastro-endoscopic examination. Images of the stomach mucosa were stored in a digitised format for subsequent evaluation. The number of ulcers and a score of severity were determined. Gastric ulceration of the squamous mucosa was identified in 82% of horses. Seventy-three (39%) horses displayed clinical signs consistent with gastric ulceration. Increasing Furr and Murray Score was associated with poor hair coat (P = 0.03), colic (P = 0.03), and increasing serum creatinine concentration (P = 0.029). There were no associations between haematology and serum biochemistry values (other than serum alkaline phosphatase concentration and serum creatinine concentration) and gastric ulceration. Our study confirmed the relatively high incidence of gastric ulceration in Thoroughbred horses involved in active race training. Gastric ulceration is a potential, but rare, cause of overt colic, but may produce more subtle detrimental effects on a horse's condition. It is concluded that the diagnosis of gastric ulceration should be based on an endoscopic examination of the stomach, although future studies are required to elucidate further the aetiology and clinical significance of gastric ulceration.