Congenital obstruction of the caudal vena cava in a dog.

A 16-week-old female Rottweiler was examined because of labored breathing and abdominal distention. Ascites, hepatomegaly, and pleural effusion were detected during physical and radiographic examinations. Selective angiography revealed a stenotic lesion at the junction of the caudal vena cava and the right atrium. A fibrous diaphragm with a pin-hole orifice was observed at surgery. Clinical signs of disease resolved after successful removal of the membranous obstruction.