Michigan Bovine TB Cases Confirmed in Two Counties

The Michigan Department of Agriculture and Rural Development (MDARD) has confirmed new cases of bovine tuberculosis (TB) in cattle herds located in Alpena and Presque Isle counties.

The infections were discovered during routine annual whole-herd testing, a process designed to catch the disease early and limit its spread.

Where Bovine TB Exists in Michigan

Bovine TB isn't new to Michigan. The disease has been established for years in the whitetail herd across parts of northeastern Lower Michigan. The state manages this through two zones:

• Modified Accredited Zone (MAZ): Alcona, Alpena, Montmorency, and Oscoda counties
• Accredited Free Zone: The rest of Michigan, including Presque Isle County

Even in the Accredited Free Zone, counties near the MAZ follow stricter testing and cattle movement rules due to the ongoing risk.

How It Spreads and Why It Matters

Bovine TB is a bacterial disease that can affect cattle, deer, and other mammals. In rare cases, it can also impact humans. According to MDARD, transmission often occurs when cattle come into contact with infected deer, making wildlife interaction the key factor.

RELATED: CWD Creeps Across Michigan: 16 Counties and Counting

State officials will conduct a full investigation, including genetic testing of the bacteria, to trace how the infection occurred. MDARD says it will continue to rely on surveillance testing, animal tracking, and wildlife management to contain the disease. Officials also stress that deer hunting in the region plays a huge part in reducing bovine TB.