Bovine brucellosis, caused by the bacterium Brucella abortus, is an economically important cause of abortions in cattle. B. abortus also affects other species including bison, buffalo and elk; some species are maintenance hosts for this organism. Infections in wildlife can hinder eradication efforts in cattle. In addition, B. abortus is a human pathogen. In humans, brucellosis can be a serious, debilitating and sometimes chronic disease that may affect a variety of organs. Most cases are the result of occupational exposure to infected animals, but infections can also occur from ingesting contaminated dairy products.
Most species of Brucella are primarily associated with certain hosts; however, infections can also occur in other species, particularly when they are kept in close contact. Maintenance hosts for Brucella abortus include cattle, bison (Bison spp.) water buffalo (Bubalus bubalus), African buffalo (Syncerus caffer), elk and camels. A feral pig population has recently been reported to maintain B. abortus. A variety of other species can become "spill-over" hosts where this organism is enzootic. B. abortus has been reported in horses, sheep, Rocky Mountain bighorn sheep, goats, chamois, pigs, raccoons, opposums, dogs, coyotes, foxes, wolves and other species.
The United States cattle herd is now free of brucellosis. Brucellosis is still present in wildlife in the Greater Yellowstone Area.
Brucellosis caused by B. abortus is a reportable disease in the U.S. All cases should be reported immediately to the state veterinarian's office.
Canine brucellosis is an infectious disease caused by the Brucella bacteria. The illness in dogs is caused by Brucella canis (B. canis). However, Brucella organisms commonly associated with other animal species, such as Brucella suis (pigs) and Brucella abortus (cattle and bison), can infect dogs depending upon their exposures to these species.
Canine brucellosis is an important cause of reproductive failure, particularly in kennels. B. canis is also a zoonotic disease, so it can affect humans. This organism causes abortions, stillbirths, epididymitis, orchitis and sperm abnormalities in dogs. Although dogs that have been spayed or neutered do not have reproductive signs, they occasionally develop other conditions such as ocular disease and discospondylitis. B. canis can persist in an animal even after antibiotic treatment.