[Pulmonary Mycobacterium avium infection in 2 domestic cats]

Two domestic cats (Abyssinian and Carthusian) presented with chronic respiratory signs including cough, respiratory sounds, and polypnea. One of the cats also showed intermittent fever. Thoracic radiographs demonstrated severe changes with predominantly micronodular interstitial lung patterns, some with mineralized areas. Bronchoalveolar lavage detected high-grade pyogranulomatous airway inflammation. A cytological examination for acid-fast bacteria and a PCR for Mycobacteria species of the bronchoalveolar lavage fluid (BALF) were negative in both cats. A culture for Mycobacteria of the BALF detected Mycobacterium avium subspecies in both cats. While the clinical signs, but not the radiographic findings, could be controlled in one cat with prolonged double antibiotic therapy, the other cat developed septic peritonitis shortly after diagnosis and was euthanized. In unexplained chronic respiratory disease in cats, mycobacterial infection should be considered as a differential diagnosis. The breed of the first patient is consistent with the known predisposition for Abyssinians.