IFNG and infection: Another cat in the same household was screened for infection using the interferon gamma release assay (IGRA), with the result being consistent with infection by non-tuberculous mycobacteria (NTM), which includes MAC; however, it had no grossly detectable disease.<h4>Relevance and novel information</h4>This case report is an unusual presentation of disseminated MAC infection in a cat, which remains a rare diagnosis.