Routine testing reveals two cases of bovine tuberculosis in Alcona and Sanilac County deer farms.
Officials say they will analyze DNA from the tuberculosis bacteria to determine where it came from. That testing is expected to take three-months.
The last time a deer farm in Michigan reported bovine T-B was in 2009. The disease is found in free-ranging deer every year in Michigan. Bovine TB can affect other mammals, including other livestock and humans.