Three cases of gastric neoplasia in psittacines.

Two adenocarcinomas of the proventriculus and an adenocarcinoma of the ventriculus are described in psittacines. All birds had evidence of digestive tract dysfunction. Hemorrhage into the lumen of the digestive tract from the ulcerated surfaces of the tumors was evident in all birds, either clinically or at necropsy. Radiographic studies, including contrast films, were useful in two cases. Alcian blue and periodic acid-Schiff stains were helpful in determining the origin of the tumor in one case.