Friday, March 07, 2008

MICHIGAN NEWS: Bovine TB Found In Deer Beyond Containment Zone

The Michigan Department of Natural Resources has confirmed that a deer harvested late in the hunting season last year in Shiawassee County, just north of Livingston County, tested positive for bovine tuberculosis.

Whether that indicates the disease has spread to this part of the state is unclear, although DNR veterinarian Dan O'Brien said such cases rarely occur in isolation.

To determine that, the DNR will test all cattle herds within a 10-mile radius of where the Shiawassee County deer was found, as well as other deer in the area. The cattle tests should be complete within six months. Animals that the tests indicate may have TB will have to be killed for further testing. The majority of deer tests will be performed during the fall hunting season.

Originally a cattle disease, bovine tuberculosis is one of three types of TB, according to the DNR's Web site. The bovine strain can infect most mammals, though transmission to humans is rare.

The DNR has known about bovine TB infections in the Michigan deer population for more than a decade, O'Brien said. Since the disease was found in wild deer in 1994, the DNR has conducted a program to control or eradicate the disease. The core area where bovine TB cases have been found is in the northeastern Lower Peninsula counties of Montmorency, Alpena, Oscoda and Alcona. Animals have tested positive for bovine TB in Antrim, Crawford, Emmet, Iosco, Mecosta, Osceola, Otsego, Presque Isle and Roscommon counties.

The TB-positive deer killed near Owosso in December more than 100 miles south of the area known as Michigan's "TB Zone."

It is too early to know whether the infection has spread.

"We'll certainly know more once we complete our surveillance testing," O'Brien said. He said it is possible the deer may have been brought to the county from the northeastern part of the state by a person.

Tuberculosis in deer is a concern for farmers as well as hunters. Once infected, deer can spread the disease to previously uninfected cattle. A bovine TB infection in a cattle herd can affect a farmer's ability to sell the cattle.

The DNR does not recommend eating animals that show signs of tuberculosis. Hunters should look for abscesses inside the rib cage or on lung tissue as a sign of TB when they field-dress their deer.

Because animals in the early stages of a TB infection do not display symptoms visible to the naked eye, thoroughly cooking meat to an internal temperature of 165 degrees Fahrenheit is the best way to kill the bacteria.

"Anybody who's adequately cooked their meat shouldn't have any problems," O'Brien said.

Hunters who believe they may have found a deer infected with TB should call the Department of Agriculture at (517) 336-5030. Those who wish to have their deer tested for TB during hunting season can drop their deer's heads off at an DNR check station.

To reduce the risk of TB infection while harvesting deer, O'Brien recommends hunters wear rubber gloves when gutting deer. One of the biggest risks of bovine TB infection for hunters is cutting themselves while processing their deer.

If you believe you may have been exposed to bovine TB or cut yourself while harvesting your deer, O'Brien recommends consulting a physician.


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