The Michigan Department of Agriculture and Rural Development (MDARD) announced March 21 that the USDA's National Veterinary Services Laboratory in Ames, Iowa, has confirmed bovine tuberculosis in the lymph nodes of a Saginaw County dairy cow identified during slaughter surveillance.
The strain of bovine TB is unique to Michigan deer and cattle."In accordance with our bovine TB response plan, the farm has been quarantined and a whole-herd test conducted," said Steven Halstead, MDARD's state veterinarian.
"Some animals responding to the on-farm test have been necropsied at Michigan State University's Diagnostic Center for Population and Animal Health (DCPAH). Samples collected at necropsy are undergoing further diagnostic tests to confirm TB and these tests may take days to weeks.
"Since Saginaw County is in a bovine TB-free area, we are moving quickly to stamp out and contain the disease at this one location."
Epidemiologists will be conducting a farm visit to look at farm bio-security measures, potential wildlife incursions including feral swine, animal husbandry practices, and purchase and sale records.
"As a partner to MDARD, DCPAH is here to help protect public and animal health in Michigan. Helping to address these types of disease incidents is core to our mission," said Carole Bolin, director of DCPAH.
UPDATE:
On March 26, MDARD reported that the laboratory results from herdmates of the Saginaw County dairy cow are also positive for bovine TB.
MDARD is testing 66 farms in a 10-mile surveillance circle around the farm to determine if there are other bovine TB exposures. The office is also conducting trace tests of cattle the farm bought or sold by the farm. If all cattle on the 66 farms test negative, Michigan’s TB-free status won’t change.
In 2011, the USDA approved all but four counties in northeastern Lower Michigan as TB-free. The Modified Accredited Zone (MAZ), where the disease still occurs, is Alcona, Alpena, Montmorency, and Oscoda counties. The Saginaw County border is approximately 115 miles and has three counties between it and the MAZ. PD
—Compiled by PD staff
