Diagnosis of a sublaryngeal abscess in a Japanese Black calf using computed tomography.

A 76-day-old Japanese Black calf presented with severe stridor, resenting palpation of the laryngeal region. Endoscopic examination revealed an expansile process restricting the esophageal and tracheal lumina caudal to the arytenoid cartilage, hyperemia and edema of the pharyngeal mucosa, right arytenoid cartilage swelling and displacement, and marked airway obstruction. The absence of an endotracheal wall abnormality impeded a definitive diagnosis. Computed tomography (CT) revealed a mass (CT value: 40-45 HU) caudal to the arytenoid cartilage, causing tracheal stenosis and esophageal displacement. The presence of gas in the mass suggested the presence of an abscess. Diagnosis of deep retropharyngeal lesions by conventional endoscopic and ultrasonographic examinations may be challenging; CT can then provide more comprehensive diagnostic information on a lesion.