Given that exposure to captive wild animals at circuses or zoos can be a source of zoonotic infection, a case and control study was carried out with a collection of exotic fowl at a zoo in Bogotá, Colombia. The presence of Mycobacterium avium-II was directly related to the death of birds kept in the original enclosure, and of 50% of a group of sentinel birds. Failure to detect the organism in a control group of birds outside the enclosure indicated that the infection was limited to the original enclosed area. We demonstrated that M. gordonae-IV was disseminated in all organs from 1 bird with macroscopic granulomatous lesion, a finding which has not been reported previously. We emphasize the importance of establishing handling norms to reduce the risk of zoonotic transmission.