A congenital pulmonary anomaly (hamartoma) in a seven-month-old bovine fetus

A case of an unusually large congenital pulmonary malformation (hamartoma) in a seven-month-old aborted Holstein fetus is reported. This was the dam's sixth gestation; the previous five had terminated in November or early December with delivery of a normal, live calf. Abortion was spontaneous without prior clinical signs noted by the herdsman. The condition of the aborted fetus indicated abortion followed closely intrauterine fetal death, which probably resulted from vascular insufficiency owing to crowding in the fetal thorax by the massive pulmonary malformation.