As the investigation into the bovine tuberculosis outbreak continues producers in South Dakota are learning more about the disease than they care to as more cattle are confirmed infected.

The Animal Industry Board sent out an update on the case April 13. Additional questions from The Cattle Business Weekly were answered on April 17.

Here’s what we know.

State and Federal animal health officials have identified two additional cases of TB residing in Harding and Butte Counties. Both herds had received the infected cows from the index herd within the past two years.

Butte County lies just to the south of Harding County. However, in the case of the Butte County cow the animal had been sold and purchased through a local sale barn approximately one year ago and was not on a ranch adjacent to the main index herd. The cow was necropsied and found to be infected.

Testing of herds adjacent to the index herd was completed as of April 14. Twelve of the 13 herds have been released from quarantine, and an infected cow was found in one adjacent herd.  The cow had been moved into this herd from the index herd approximately two years ago.

 “A total of three affected herds have been identified in this outbreak.  The index herd will be depopulated by the end of the week.  We are working with the other two herds, each with only one infected cow that originated in the index herd, to determine appropriate testing to assure freedom from disease,” State Veterinarian Dusty Oedekoven says.

Due to a large number of feeder heifers from the main index herd now residing in eastern South Dakota as breeding heifers, the Animal Industry Board will host a meeting April 19, 7 p.m. in Sisseton at the Roberts Co. 4-H Grounds.

“There are concerns there, similar to the concerns in Harding County when the disease was first detected.  The goal of the meeting will be to provide information about Bovine Tuberculosis and the response to this outbreak,” says Oedekoven.


The TB investigation began in February when three beef cows were identified with TB during routine slaughter inspection in two Nebraska beef packing plants. Through records the cattle were traced back to a ranch in Harding County. Since then the index herd, adjacent herds and trace out herds have undergone testing. Over a dozen states have become involved in the investigation.

Samples collected from the index herd and submitted to the National Veterinary Services Laboratory in Ames, Iowa found a strain of bacteria nearly identical to a strain known to exist in dairy cattle in the Central region of Mexico. The strain has not previously been identified in the United States and at this time it is not known how the strain manifested in South Dakota.

All are encouraged to check the Animal Industry Board website at to learn more.