Congenital Segmental Absence of Tracheal Rings in a Kitten.

Congenital anomalies of the trachea are rare in cats. This article reports segmental absence of tracheal cartilage rings in a kitten. An 8-month-old female kitten was presented with a history of weight loss and respiratory distress for 2 months. Radiographs of the thorax demonstrated a large air-filled sac suggestive of pneumomediastinum. No cartilaginous structures were evident radiographically over the caudal portion of the trachea. At necropsy examination, approximately 2 cm from the carina, a 3 cm segment of the trachea lacked cartilaginous rings. The clinical and morphological features of this lesion were similar to those described in human and canine cases of congenital segmental absence of tracheal rings.