Total anomalous pulmonary venous connection in a chicken.

This report describes a case of total anomalous pulmonary venous connection (TAPVC) in a 5-wk-old male white leghorn chicken that presented with growth retardation. This chicken was a specific-pathogen-free chicken bred in an isolator. At 5 wk of age, the chicken was euthanatized and autopsied. Macroscopically, the right ventricle and right atrium were significantly enlarged whereas the left atrium was small and blind-ending with no connection to the pulmonary veins. The pulmonary veins were connected directly to the right atrium. The above abnormality was accompanied by an ostium secundum-type atrial septal defect. No other malformations were observed. TAPVC is a very rare congenital cardiac abnormality that has not been reported in avian species to date.