Systemic Mycobacterium caprae infection in a domestic cat in the United Kingdom: a case report

Abstract This report describes the first documented case of Mycobacterium caprae ( M. caprae ) infection in a domestic cat (Felis catus) in the United Kingdom. The affected cat was a male-castrated Bengal breed that presented with respiratory symptoms and progressive weight loss. Clinical signs were unresponsive to antibiotics and anti-inflammatory therapy. Postmortem examination and histopathology revealed severe chronic pyogranulomatous bronchopneumonia with necrosis and acid-fast bacilli, which were identified as M. caprae via PCR and culture. While primarily a pathogen of goats, M. caprae poses zoonotic risks and requires specialized diagnostics. This case emphasizes the need for interdisciplinary collaboration to address emerging zoonotic threats.