Congenital peritoneopericardial diaphragmatic hernia was diagnosed in a 2‐week‐old sable antelope (Hippotragus niger) calf with subsequent fatal acute heart failure. Histopathological examination of the lung, liver and heart revealed lesions supportive of acute heart failure that consisted of pulmonary oedema, periacinar hepatocellular necrosis and myocardial degeneration and necrosis. The external pressure on the coronary arteries by the liver and abomasum most likely resulted in ischaemic injury of the cardiomyocytes and the resultant acute heart failure.