Clinical findings and treatment of disseminated ‘Mycobacterium avium subspecies hominissuis’ infection in a domestic cat

KANEGI, Ryoji; YASUGI, Mayo; NABETANI, Tomoyo; TANAKA, Toshiyuki; WADA, Yusuke; HIRAI, Kotaro; SUGIURA, Kikuya; HATOYA, Shingo

Infections of Mycobacterium species in domestic cats have been reported sporadically. In Great Britain, previous reports have revealed that 1.16% of 11,782 feline tissue samples submitted to diagnostic laboratories were confirmed to have Mycobacterium infections [10] , and 15% of cultured Mycobacterium species were M. avium. In Japan, Mycobacterium infections in domestic cats have been historically uncommon, with only two cases reported: unclassified Mycobacterium species (MFM001 strain) [13] and MAH in the Kanto region [20] . This is the third reported case of Mycobacterium species infection in a domestic cat in Japan. In Japan, pulmonary NTM diseases are commonly diagnosed in human medicine with an incidence rate of 14.7 cases per 100,000 person-years in 2016, which is 2.6 times higher than the incidence rate reported in 2007 [25] . The most common pathogens of pulmonary NTM diseases were M. avium in the northern and eastern parts of Japan and M. intracellulare in the southern and western parts of Japan. Mycobacterium infection should also be considered a potential disease for domestic cats. In a previous study in Australia, it was observed that certain lines of Abyssinian and Somali cats likely suffer from a familial immunodeficiency that predisposes them to infection with slow-growing mycobacteria, including M. avium [2] . Whilst immunological predisposition of those breeds has not been well proven, it will be beneficial to pay attention to the breed of cats with suspected Mycobacterium infections.