Submitted to: Journal of Zoo and Wildlife Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2006
Publication Date: 12/1/2006
Citation: Harrentien, L.A., Finnegan, M.V., Woodford, N.L., Mansfield, K.G., Waters, W.R., Bannantine, J.P., Paustian, M., Garner, M.M., Bakke, A.C., Peloquin, C.A. 2006. Mycobacterium avium in Pygmy Rabbits (Brachylagus Idahoensis): 28 Cases. Journal of Zoo and Wildlife Medicine. 37(4):498-512. Interpretive Summary: The Columbia basin pygmy rabbit is an endangered species and captive propagation efforts are being used to increase the population size for reintroduction of this species back into native habitats. Captive propagation efforts have been hindered by disease, most notably avian tuberculosis. In this study, avian tuberculosis of captive pygmy rabbits was described including clinical, therapeutic, immunologic, and pathologic aspects of the disease. Specific risks factors and recommendations for diagnosis and treating the disease were determined. These findings should prove beneficial for other captive propagation and re-introduction programs.
Technical Abstract: The Columbia basin pygmy rabbit (Brachylagus idahoensis) was listed as an endangered species by the United States Fish and Wildlife Service in November 2001, and captive propagation efforts have attempted to increase population size in preparation for reintroduction of animals into central Washington. Disease has been a significant concern in captive populations, and disseminated mycobacteriosis due to Mycobacterium avium has been the most common cause of death of adult captive pygmy rabbits. Fatal disseminated mycobacteriosis due to M. avium was diagnosed in 28 captive pygmy rabbits between June 2002 and September 2004, with deaths occurring at 2 of the 3 captive holding facilities. Antemortem and postmortem medical records from these cases were evaluated retrospectively and epizootiological data obtained, with the goals of describing the clinical behavior of mycobacteriosis in pygmy rabbits, relative value of physical examination findings and diagnostic test results in the presumptive or definitive diagnosis of mycobacteriosis in pygmy rabbits, use of various treatment protocols, possible risk factors for the observed high mortality, and recommendations for prevention of mycobacteriosis. The high morbidity and mortality of M. avium infection in pygmy rabbits appears due to partially-ineffective cell-mediated immunity.