Successful Treatment of Mycobacterium caprae Infection in Two UK Cats

A 4-year-old, male-neutered Savannah cat (Case 1) and a 3-year-old female-neutered British shorthair cat (Case 2) were each investigated for chronic coughing, lethargy and weight loss. Thoracic imaging revealed diffuse broncho-interstitial changes and multifocal soft-tissue nodules (Case 1), and two cavitating masses in the left lung (Case 2). Bronchoalveolar lavage cytology (BAL) in both cases identified macrophagic inflammation with acid-fast bacilli and was culture (Case 1) or PCR (Case 2) positive for Mycobacterium caprae. The cats were treated with 11 months (Case 1) and 9 months (Case 2) of triple antimicrobial therapy comprising pradofloxacin (5 mg/kg orally once every 24 h), rifampicin (10 mg/kg orally once every 24 h) and azithromycin (15 mg/kg orally once every 24 h). Both made complete clinical recoveries and radiographic improvement in the thoracic changes were static for 2 months prior to cessation of therapy. Both cats remain clinically well 12 and 10 months after cessation of treatment, respectively.