Tuberculosis due to in pet cats associated with feeding a commercial raw food diet.
Conor O'Halloran, Olympia Ioannidi, Nicki Reed, Kevin Murtagh, Eili Dettemering, Stefaan Van Poucke, John Gale, Julie Vickers, Paul Burr, Deborah Gascoyne-Binzi, Raymond Howe, Melanie Dobromylskyj, Jordan Mitchell, Jayne Hope, Danièlle Gunn-Moore
Author Information
Conor O'Halloran: 1 Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Edinburgh, UK. ORCID
Olympia Ioannidi: 2 Anderson Moores Veterinary Specialists, Winchester, UK. ORCID
OBJECTIVES: , a member of the complex, can infect cats and has proven zoonotic risks for owners. Infected cats typically present with a history of outdoor lifestyle and hunting behaviour, and cutaneous granulomas are most commonly observed. The aim of this study is to describe an outbreak of tuberculous disease commencing with six young cats, living exclusively indoors in five different households across England, being presented to separate veterinarians across the UK with a variety of clinical signs. METHODS: Investigations into the pyogranulomatous lesions, lymphadenopathy and/or pulmonary disease of these cases consistently identified infection with . Infection was confirmed by PCR, where possible, or was indicated with a positive interferon-gamma release assay (IGRA), where material for PCR was unavailable. In-contact, cohabiting cats were screened by IGRA and follow-up testing was undertaken/advised where results were positive. A lifestyle investigation was undertaken to identify the source of infection. RESULTS: Six clinically sick cats and seven in-contact cats were identified with evidence of infection. Five clinical cases were either too sick to treat or deteriorated despite therapy, giving a mortality rate of 83%. Lifestyle investigations revealed the common factors between clusters to be that affected cats had mycobacterial infections speciated to , were exclusively indoor cats and were fed a commercially available raw food product produced by a single manufacturer. The Food Standards Agency, Animal & Plant Health Agency, Public Health England and the food manufacturer concerned have been notified/informed. Other possible sources of exposure for these cats to were explored and were excluded, including wildlife contact, access to raw milk, the presence of rodent populations inside the buildings in which the cats lived and exposure to known infectious humans. CONCLUSIONS AND RELEVANCE: Upon investigations, our results provide compelling, if circumstantial, evidence of an association between the commercial raw diet of these cats and their infections.