Abstract
This report describes a case series of granulomatous inflammation in the tails of seven immunocompromised mice. The disease was associated with Mycobacterium chelonae infection. The source and route of infection remained unclear. Spontaneous infection with M. chelonae has not previously been documented in mice. We conclude that M. chelonae, like in humans, should be considered as a facultative pathogen in laboratory animals, particularly under immunosuppressive conditions.