Bovine tuberculosis (mycobacterium bovis or M. bovis) is a mycobacterium that can cause disease in large animals, including bison, elk, cattle, and deer. In rare cases, M. bovis can cause tuberculosis in humans, causing infection in the lungs and lymph nodes. In the past, M. bovis transmission between cattle and humans was more common, but now, with focus on disease control and pasteurization, it accounts for less than 2% of the tuberculosis cases in the United States.