Tracheal granuloma because of infection with a novel mycobacterial species in an old FIV-positive cat.

Abstract

A 15-year-old domestic shorthair feline immunodeficiency virus-positive cat was presented with a five day history of productive cough and acute respiratory distress. Physical examination revealed inspiratory dyspnoea and diffuse gingivostomatitis. Radiographs showed an intratracheal mass located at the level of the sixth and the seventh cervical vertebrae. Bronchoscopy revealed a unique intratracheal mass occluding about 85 per cent of the tracheal lumen. The tracheal mass was removed bronchoscopically. A diagnosis of pyogranulomatous inflammation referable to a mycobacterial infection was made based on cytological and histopathological findings. 16S rRNA polymerase chain reaction testing and sequence analysis identified a novel mycobacterial species, likely a slow grower, with 95 per cent identity with Mycobacterium xenopi. To our knowledge, this is the first description of a tracheal mycobacterial granuloma in a cat, and the first time, a mycobacterium with this sequence has been identified.