Brucellosis in Free-Ranging Bison (Bison bison) in Yellowstone, Grand Teton, and Wood Buffalo National Parks: A Review

Meyer, Margaret; Meagher, Margaret

Brucellosis, caused by Brucella abortus, is enzootic among the free-ranging bison (Bison bison) herds in Yellowstone and Grand Teton National Parks (Wyoming, USA), and Wood Buffalo National Park (Alberta, Canada). In contrast to previous assumptions, we present evidence that the response of bison to infection with B. abortus differs significantly from that of cattle. One marked difference is in their response to immunization with strain 19. In contrast to previous assumptions, the authors present evidence that the response of bison to infection with B. abortus differs significantly from that of cattle. One marked difference is in their response to immunization with strain 19. In contrast to the 65 to 80% efficacy of strain 19 in the immunization of bovine calves, it stimulated no immunity in bison calves. Additionally, when used for immunizing adult cattle, it caused less than 2.5% to abort, while in adult bison it caused 70% to abort. Additional differences between cattle and bison occurred in the low frequency of abortions in natural infections among bison and also in the comparatively few recoveries of B. abortus from tissues of seroagglutination positive bison. Among seroagglutination-positive cattle, B. abortus can be recovered from 86 to 95% of tissue samples. Among 218 Yellowstone National Park bison shot during the winter of 1992, B. abortus was recovered from 26 of 109 seroagglutination positive animals and 22 (85%) of the isolates were from subadults. Based on available data, the authors believe the risk of transmission of brucellosis from free-ranging bison to cattle herds is very low.

Brucellosis in Free-Ranging Bison (Bison bison) in Yellowstone, Grand Teton, and Wood Buffalo National Parks: A Review

Series