Gastric ulcer accounts for an important cause of abdominal discomfort in young horses. Concerning either the presence or absence of clinical signs and their variations, the lesions location in the gastric mucosa and complications resulting from ulcerative lesions, four clinical syndromes have been described in foals: 1) Asymptomatic or silent ulcers; 2) Symptomatic or active ulcers; 3) Perforated ulcers; and 4) Gastric or duodenal obstruction. With the aim of studying the distribution of lesions (ulcers and/or erosions) and desquamations from the non-glandular epithelium in the gastric mucosa of young horses and a possible relationship between both alterations (lesion/desquamation), sixty Quarter Horse foals without signs of gastric disease underwent gastroscopy.

Foals were divided by age in four groups of 15 animals as follows:

1 to 30 days, 31 to 60 days, 61 to 90 days and 91 to 120 days. Lesions were most prevalent in the stratified squamous epithelial mucosa mainly adjacent to the margo plicatus along the greater curvature followed by squamous mucosa next to the cardia along the lesser curvature, glandular and non-glandular fundus and antrum. Regions of the fundus and margo plicatus were similarly affected by desquamations. There was no association between lesions and desquamations occurrence