Computed tomographic appearance of choanal atresia in an alpaca cria.

A 6-hour-old alpaca cria was admitted for evaluation of respiratory distress since birth. Contrast radiography confirmed the presence of bilateral choanal atresia, and computed tomography (CT) evaluation was planned to aid in the surgical treatment. Due to deterioration in the cria's condition, euthanasia was performed prior to the CT examination. Postmortem CT examination was performed to determine the appearance of choanal atresia. The embryology and CT appearance of choanal atresia is discussed.