EXPERIMENTAL STUDIES ON BRUCELLA ABORTUS IN MOOSE (ALCES ALCES)

Four moose (Alces alces) were inoculated conjunctivally with B. abortus biovar 1 to determine their susceptibility to brucellosis, and to describe the serology, bacteriology, hematology, clinical chemistry, and pathology associated with infection. All moose became infected. Two moose were killed at day 70 post-exposure, one (83F) died acutely at day 85, and one was killed at day 166. None of the moose had clinical signs, except for 83F immediately before death. Infected moose were readily detected serologically by the buffered antigen plate test, Brewer card test, standard tube agglutination test, and complement fixation test as used for brucellosis in cattle. With the exception of samples from 83F taken 24 hours before death, clinical chemistry, and hematology results were stable for all moose, and similar to normal values seen in cattle. Lesions seen in all moose were indicative of endotoxemia, and moose 83F died of acute endotoxic shock. Brucella abortus biovar 1 was isolated from several tissues in all moose, most notably from lymph nodes where counts often exceeded 4 × 104 colony forming units per g of tissue. Thus infection with B. abortus will kill moose, and progression of the disease is likely rapid under field conditions. Moose appear to be a dead-end host for brucellosis.