Mycobacterium tuberculosis in a red-crowned parakeet (Cyanoramphus novaezelandiae)

An adult female red-crowned parakeet (Cyanoramphus novaezelandieae) was presented for necropsy and histopathologic evaluation. The bird had died after exhibiting lameness, weight loss, respiratory signs, and hemoptysis. Postmortem radiographs revealed lesions in the diaphysis of the left femur and soft-tissue opacities in the lungs. At necropsy, the muscles of the left femur were pale and swollen, white-yellow small nodules were visible in lungs and air sacs, and the liver and other coelomic organs appeared pale. On histologic examination, areas of necrosis in the lungs were extensively infiltrated with acid-fast positive bacilli surrounded by macrophages, epithelioid cells, and giant cells. Acid-fast bacilli were also present in the left leg muscle and in granulomas in the liver, kidneys, and intestine. Fungal hyphae associated with a Splendore-Hoeppli phenomenon were visible in the left leg muscle. Mycobacterium tuberculosis was confirmed by polymerase chain reaction testing performed on muscle samples. Results were indicative of infection with M tuberculosis complicated by mycotic myositis. The disease in avian species is of zoonotic importance, and infected birds may be a useful sentinel for human infection.