The bilateral ductus arteriosus with tetralogy of Fallot was detected in a 64-day-old female mixed breed between Holstein and Japanese black. The patent left ductus arteriosus was normal position on the left side. The obliterated right ductus arteriosus connecting the brachiocephalic trunk and the right pulmonary artery was observed on the right side. The proximal portion of the right pulmonary artery was atretic.
