October 26, 2007

 

US state of Minnesota reports TB infection in cattle herd

  

 

The Minnesota Board of Animal Health announced that a heifer from a farm in Beltrami County tested positive for bovine tuberculosis (TB).

 

Minnesota has now detected bovine TB in eight beef herds in Roseau and Beltrami counties, according to the Minnesota Farm Guide.

 

The Beltrami County beef cattle herd was quarantined last year after an investigation revealed the owner had purchased two animals from a TB infected farm.

 

However, the owner's entire herd tested negative at that time.

 

It was during the second follow-up herd test conducted this fall, that the two animals tested were suspected of bovine TB.

 

Tissue samples were submitted to the National Veterinary Services Laboratory (NVSL) in Ames, Iowa and bovine TB was confirmed in the 12-month-old beef heifer on Oct. 23. The second animal was negative.

 

The USDA is coordinating the details of indemnification and depopulation. State and federal officials have already implemented tracing measures for all animals that had gone into or out of the farm.

 

Minnesota Board of Animal Health Executive Director and State Veterinarian Dr. Bill Hartmann said the new finding may be explained by the way bovine TB spreads and develops.

As Bovine TB is caused by slow growing bacteria with a long incubation period, it is crucial to test high-risk herds twice, said Hartmann.

 

The state is now continuing its TB testing in cattle herds statewide.

 

The testing began prior to the discovery of this infected herd and is expected to be completed by the end of the year.

 

The department aims to test 1,500 herds, and 1,200 have already been tested. So far, all results have been negative.

 

The Minnesota Department of Natural Resources (DNR) plans to continue testing hunter-harvested white-tailed deer in the affected area of northwest Minnesota this fall. Over 2,000 deer have been tested in this area since 2005 and 13 deer have tested positive for the disease. All TB-positive deer were found in a small, localized area.

 

Thanks to preventative measures taken by the beef and dairy industries, cattle infected with bovine TB pose little risk to human health.

 

The United States has actively pursued a bovine TB eradication programme since 1917. These are implemented through food safety initiatives such as milk pasteurization and inspection of internal organs at slaughter.