Eisenmenger's complex in a Holstein-Friesian cow.

A 4.5-year-old, Holstein-Friesian cow presented with a 1-month history of severe exercise intolerance. Rectal examination and transrectal ultrasonography revealed a large mass in the left retroperitoneum. The heart rate was 70 to 80/min. Premature ventricular complexes and ventricular bigeminy were present on an electrocardiogram. Erythrocytosis was present and blood gas analysis revealed marked hypoxaemia. An echocardiogram demonstrated a large ventricular septal defect, a partially dextroposed aorta, and concentric hypertrophy of the right ventricular free wall. Colour flow Doppler echocardiography and a contrast echocardiographic study demonstrated a right-to-left shunt through the ventricular septal defect. Eisenmenger's complex was diagnosed. The patient was euthanased. Necropsy confirmed the gross cardiac lesions identified by echocardiography and an abscess in the apex of the left ventricle. Severe pulmonary arterial lesions were present, consistent with a marked increased in pulmonary vascular resistance. Actinomyces pyogenes was cultured from abscesses of the retroperitoneum and the ventricular apex.