A Dane County dairy herd has tested positive for bovine tuberculosis, according to the Wisconsin Department of Agriculture, Trade and Consumer Protection. This is the first reported case of bovine TB in Wisconsin since 1980.
Meat inspectors identified a carcass during a routine slaughter inspection and sent a sample to the National Veterinary Services Laboratory for testing. Through animal identification records, the carcass was traced back to a herd in Dane County that DATCP immediately quarantined. A quarantine prevents any animals from moving on or off of the farm.
DATCP officials are tracing all animals that have moved off the farm over the last five years.
Federal agriculture officials typically record about 8 cases nationwide annually. The last instance of bovine TB in Wisconsin was in the mid-1990s.
Agriculture officials say the strain of bovine TB in the cows matches a strain found in a Maier Farms worker in 2015, indicating the worker may have infected the herd. Animals often don’t show signs of infection until the disease reaches an advanced stage, which can take years.
“We are working closely with the herd owner, U.S. Department of Agriculture, Department of Health Services, area veterinarians, industry partners and other herd owners. We are taking aggressive measures to control and prevent the spread of this disease,” said Dr. Darlene Konkle, DATCP’s acting State Veterinarian. “Our staff and partners train for these types of responses and are taking the necessary steps to protect animal and human health.”
Pasteurized milk continues to be safe to consume. The pasteurization process, which destroys disease-causing organisms in milk by rapidly heating and then cooling the milk, eliminates the disease from milk and milk products.
Bovine TB is most commonly spread to humans through consuming unpasteurized milk or milk products from infected animals, and close contact with infected animals or people. Also, infected people can be a source of infection to animals. More information about human TB is on the Centers for Disease Control website.
Food safety laws prevent meat from infected animals from entering the food chain. State and federal inspectors at slaughter plants evaluate live animals and animal products for signs or symptoms of disease and remove any from entering food production.
Bovine TB is a respiratory disease of cattle that does not spread easily. It is a chronic, slowly progressive disease meaning it can take months to years to worsen, grow, or spread.
Infected animals may pass the infection to other animals even if they appear healthy. Animals often do not show signs until the infection has reached an advanced stage.
The U.S. has nearly eliminated bovine TB due to the National Tuberculosis Eradication Program. Wisconsin has been certified as TB-free since 1980. With a thorough investigation and containment of an outbreak Wisconsin will maintain its TB-free status with USDA.