Helena, Mont. – The Department of Livestock (DOL) is investigating ties to Montana cattle from a tuberculosis (TB) infected herd in South Dakota. Montana is focusing on three distinct groups of animals: Contact herds – herds that have shared pasture or fence line contact with the affected herd; Herds that have supplied animals to the affected herd; and Herds that have received animals from the affected
this time, two Montana cattle herds that had contact with the South Dakota positive animals must undergo a tuberculosis test to confirm that the disease has not spread. Additional herds may be identified as the investigation progresses. The likelihood that Montana herds are infected is extremely low, however, the department is conducting a thorough investigation.
“Following up on interstate movements after a detection of TB or other animal disease is a routine part of disease investigations,” said Tahnee Szymanski, Assistant State Veterinarian. “Our strong working relationship with South Dakota is critical in promptly identifying animal movements and protecting the state of Montana.”
Bovine TB is caused by the bacteria Mycobacterium bovis. The disease causes granulomatous lesions inside the lymph nodes, lungs, liver, spleen, and skin of affected animals. The primary route of spread is aerosol transmission to other animals in close contact. The bacteria is also capable of infecting wildlife, such as deer, and people. The disease has an incubation period that can range from months to years and infected animals may show no clinical signs until later stages of infection, meaning healthy appearing cattle may be infected with the bacteria.
Although TB is a zoonotic disease capable of infecting people, it is not a food safety threat, thanks to a robust meat inspection program and the pasteurization of milk for retail