LANSING, Mich. — Michigan state officials have established an area in five Michigan counties as a Potential High Risk Area for Bovine tuberculosis (TB) earlier this month after several wild deer came up positive for TB.

 

The designation came as a result of four free-ranging whitetail deer testing positive for bovine TB, which was confirmed by Michigan’s Department of Natural Resources. The deer were located in Iosco, Oscoda, Presque Isle and Roscommon counties, all of them either in the TB endemic zone or near it. These counties are in the northeastern portion of the Lower Peninsula (L.P.).

 

This designation requires all cattle and bison herds located within a 6.2-mile radius of a TB-positive deer to be tested for bovine TB within six months. Cattle and bison herds are tested to ensure the disease has not spread from local deer to those animals.

 

This “not only protects Michigan’s cattle industry, but also helps reassure the state’s trading partners that all necessary steps are being taken to protect the health of the herds,” said a statement from the Michigan Department of Agriculture and Rural Development (MDARD).

 

Also, last week the agency said a small beef cattle herd in Alcona County was recently confirmed as bovine TB-positive by MDARD. The herd was identified through routine surveillance testing. Although at one time a cattle herd with even one TB-positive animal had to be depopulated, or put down, that is no longer the case, said Assistant State Veterinarian Rick Smith.

 

Cattle herds are too big now to be indemnified, he explained. Instead, the state has a formula it uses to test such a herd and, as long as there aren’t too many infected cattle and the herd can be verified as TB-free over a period of time, it is left alone. Alcona County is located in a four-county TB endemic area in the northeastern L.P., also known as the Modified Accredited Zone (MAZ). The MAZ is a USDA designation.

 

The state has been battling bovine TB for more than 20 years and has been making great strides towards getting the whole state to TB-free status. “In the Modified Accredited Zone, any shared contact between deer and cattle can be a potential source of bovine tuberculosis infection,” Smith said. “Preventing deer from having contact with cattle feed, feed storage or watering areas is crucial for farmers in this area of Michigan.” Within the MAZ, cattle herds are required to undergo annual whole herd tests and be tested before movement.

 

In addition, all cattle in Michigan are required to have electronic identification ear tags, also known as RFID tags, before they are moved from a farm. According to MDARD, this requirement helps officials trace cattle movement in the event of a disease investigation.

 

Bovine TB is a bacterial disease primarily affecting cattle. The disease can be spread between wildlife populations and other mammals, including humans. It’s believed that bovine TB occurring in cattle herds is usually spread from whitetail deer that have contact with cattle via water where deer and cattle both drink, or from feed.

 

MDARD has developed plans for ranchers to try to stop this from happening. The MAZ in Michigan likely exists at all because there’s a great deal of privately held land in that area that property owners use to cultivate large deer populations.

 

More information about bovine TB in Michigan can be found online at www.michigan.gov/bovinetb