An eleven year old, spayed female French bulldog with pituitary-dependant hyperadrenocortism with a cardiac murmur and gallop rhythm presented with dyspnea, tachypnea, adventitious lung sounds, and weak pulses. Pleural effusion and a heart-based mass were demonstrated via radiography and echocardiography. The dog died while receiving supportive care. Necropsy and histopathology revealed a large aortic body carcinoma with vascular invasion and metastatis to a local lymph node. The cardiac ventricles were hypertrophied with dilated chambers. Within the left ventricle there was an exophytic polypoid mass which histologically resembled hemangiosarcoma. Evidence of cardiovascular decompensation was present, including hydrothorax, hydropericardium, ascites, and hepatic congestion.