Abstract
A 6-month-old female Holstein calf was referred with a history of respiratory distress, anorexia and dehydration. When first examined, a loud harsh murmur was clearly audible from both sides of the thorax. Two-dimensional echocardiography demonstrated a markedly dilated right ventricle and right atrium, hypertrophied myocardium, prominent papillary muscles and a thickened interventricular septum (IVS). A large-sized ventricular septal defect was imaged at the top of the IVS. The aorta was dextrally located and overriding both ventricles. The diagnosis was confirmed as tetralogy of fallot on postmortem examination.