CANINE-DISTEMPER EPIZOOTIC IN LIONS, TIGERS, AND LEOPARDS IN NORTH-AMERICA

Canine distemper virus (CDV) infection occurred in captive leopards (P anthera pardus), tigers (Panthera tigris), lions (Panthera leo), and a jaguar (Panthera onca) in 1991 and 1992. An epizootic affected all 4 types of cats at the Wildlife Waystation, San Fernando, California, wi th 17 mortalities. CDV-infected raccoons were thought to be the source of infection in these cats. Two black leopards died at the Naibi Zoo, Coal Valley, Illinois, and 2 tigers died at the Shambala Preserve, Ac ton, California. Initial clinical signs were anorexia with gastrointes tinal and/or respiratory disease followed by seizures. Canine distempe r virus was isolated from 3 leopards, 3 tigers, and 3 lions that died or were euthanized when moribund. Monoclonal antibody testing identifi ed the virus isolates as CDV. Gross and histopathologic findings were similar to those found in canids with distemper with a few exceptions. There were fewer lesions in the brain, and there was a pronounced typ e 2 cell proliferation in the lung, with inclusion bodies and CDV anti gen demonstrated by immunohistology. Neutralizing antibody to CDV was found in high titers in serum from most animals but was absent or was found only in low titers in some cats that succumbed after CDV infecti on. There was a marked difference in neutralizing antibody titers when tests were done with different strains of CDV.