Acute tracheal compression in a large breed dog due to a dorsal tracheal membrane abscess

Abstract

To describe a case of acute tracheal compression due to a dorsal tracheal membrane abscess in a dog. A 3-year-old intact male Bluetick Coonhound presented for evaluation of 36 hours of marked inspiratory dyspnea and stridor. A radiographic diagnosis of tracheal collapse was made on thoracic radiographs, which was confirmed to be static compression by tracheoscopy. Dorsal extraluminal tracheal compression from a fluid filled structure adjacent to the trachea was suspected based on ultrasonography. Endoscopic-guided transtracheal fine needle aspiration yielded septic suppurative inflammation. At surgery an abscess in the dorsal tracheal membrane was identified, lanced, and lavaged, which resulted in restoration of normal tracheal diameter. The dog developed bilateral pneumothorax, which was treated medically by thoracostomy tube placement and manual evacuation of the accumulated air. Postoperative radiographs also revealed evidence of pneumomediastinum. Pneumothorax and pneumomediastinum likely occurred secondary to the surgical approach, worsened by positive pressure ventilation. Cultures of the abscess isolated a nonhemolytic Streptococcus species but with no evidence of anaerobic bacteria. The dog made a full functional recovery. Tracheal compression is a rare diagnosis in dogs. To the authors' knowledge, this represents the first report of an abscess in the dorsal tracheal membrane, diagnosed by endoscopic-guided transtracheal fine needle aspiration, causing clinically relevant acute tracheal obstruction.