Mastocytoma and gastroduodenal ulceration. Gastric and duodenal ulcers in dogs with mastocytoma.

Twenty of 24 dogs with mastocytoma had ulcers of the gastroduodenal mucosa. The ulcers were more frequent in the stomach, less frequent in the duodenum. Perforating ulcers caused death in 3 dogs. Vascular lesions were frequent in these dogs, and it was considered that the vascular alterations may have contributed to the gastroduodenal ulceration associated with mast-cell neoplasms.