Mycobacterial osteomyelitis in captive marsupials.

Mycobacterial osteomyelitis was detected in 3 marsupials exhibited at the National Zoological Park, Washington, DC. One Matschiei's tree kangaroo (Dendrolagus matschiei), 1 Parma wallaby (Macropus parma), and 1 long-nosed rat kangaroo (Potorous tridactylus) were affected. The Parma wallaby had disseminated granulomatosis. Acid-fast organisms were observed in the bone marrow of the wallaby, using the auramine-O-rhodamine fluorescent technique; however, cultures were negative. The tibiotarsal joint of the rat kangaroo contained exudate, with fistulous tracts and necrosis of the articular surface. Granulomas with necrotic centers from this area were positive by auramine-O-rhodamine but were negative on culture. The tree kangaroo had thickening of the right ischium, with a pocket of exudate caudal to the acetabulum. The musculature in the acetabular area was thickened and fibrotic. Mycobacterium avium serotype 15 was isolated from the ischium and liver of this animal.