One four-month-old female shepherd mongrel dog with chief complaints of abdominal distension and dysponea was referred. The authors performed physical examination, hematological examination, X-ray examination, exploratory laparotomy, electrocardiography and angiography as antemortem investigation in addition to postmortem examination. This patient revealed complicated congenital cardiac anormaly including patent ductus arteriosus, both atrial and ventricular hypertrophy, distension in the base of the pulmonary artery, pulmonary stenosis, aortic insufficiency, patent foramen ovate and coronary arteriovenous fistula.