Disseminated mycobacteriosis due to Mycobacterium avium in captive Bengal tiger (Panthera tigris)

A 2-year-old captive female Bengal Tiger (Panthera tigris) died after prolonged anorexia in the Gwangju Uchi Park Zoo, Gwangju, Republic of Korea. Necropsy revealed multiple nodules of varying sizes in the lung, liver, kidney, and spleen. Histopathologic examination revealed a typical granuloma composed of caseous necrotic areas surrounded by lymphocytes with a few giant cells and foamy macrophages. Periodic acid-Schiff stain and Gomori methenamine silver stain did not reveal any fungal bodies. The Ziehl-Neelsen acid-fast stain revealed few acid-fast organisms in the lung, liver, kidney, and spleen. A polymerase chain reaction assay of the lung, liver, kidney, and spleen yielded a positive result for Mycobacterium avium subsp. avium. This is an unusual case of disseminated infection of a wild mammal with avian mycobacteriosis, and is believed to be most likely associated with the feeding of tigers with culled chickens infected with M. avium.