Bovine tuberculosis confirmed in South Dakota steer, investigation continues

PIERRE, S.D. — A case of Bovine tuberculosis has been confirmed in a beef steer from South Dakota, marking the first case in the state since 2021. The infection was detected through routine meat inspections and is currently under investigation to trace its origin.

According to Beth Thompson, South Dakota state veterinarian and executive secretary of the South Dakota Animal Industry Board, the infected steer was identified in late October during routine inspection at a Wisconsin packing plant.

“When cattle are slaughtered at inspected plants, there are trained inspectors who look at the carcass at various points in the process,” Thompson said. “This steer was found at slaughter, meaning an inspector noticed some sort of pathology, pulled the animal, and submitted samples.

The United States Department of Agriculture Animal and Plant Health Inspection Service’s National Veterinary Services Laboratories in Ames, Iowa, confirmed samples Nov. 5 from a beef steer to be tuberculosis positive by PCR. The culture isolate recovered was reported Dec. 6 to be Mycobacterium bovis.

Records from the packing plant linked the animal to a feedlot in Hamlin County, South Dakota. However, additional investigation is ongoing to identify the source herd from which the animal originated.

“The traceback was fairly quick and easy on this animal, to the feed yard,” Thompson said. “The slaughter plant had records which identified the farms who had contributed to the load. We now need to determine the origin of the steer, as it was moved onto the feedlot.”

The State Veterinarian’s office is working closely with the feedlot owner as well as other producers who may have sold animals purchased by the feedlot, USDA officials, and area veterinarians to locate the steer’s source herd. Necessary precautions are being taken to protect the health of South Dakota’s cattle industry.

“One of our field veterinarians is working closely with the feedlot owner as a point of contact,” Thompson said. “The work we are doing now with both the feedlot owner and the source herds includes testing and tracking animals via records. The herd owners we are working with in this investigation have been very cooperative, and we have started TB testing.”

Bovine tuberculosis is a chronic, slow-progressing respiratory disease that primarily affects cattle. While infected animals can transmit the disease to others in close contact, cattle rarely exhibit visible signs of illness. This makes it difficult to detect without regular testing.

The disease was nearly eradicated in the United States due to a longstanding campaign, and the disease is now rare. South Dakota has been recognized as free of bovine TB since 1982, and this is the first case in the state in over three years.

Thompson wants the public to be reassured that Bovine tuberculosis does not pose a threat to food safety in the United States, specifically thanks to strict pasteurization and meat inspection processes.

“There are trained personnel in the plants, looking at the carcasses and watching the slaughter process,” Thompson said. “They are trained to detect pathologies, and are also trained in other areas of food safety at a plant level. The risk of infection from eating meat from an infected animal is low; the main risk is to the plant employees who handle the carcasses.”

For further updates on the investigation and precautions being taken, contact the South Dakota Animal Industry Board or USDA APHIS.

Kennedy is a reporter for Agweek based out of South Dakota. She grew up on an organic crop farm where her family also raises cattle in eastern South Dakota. She graduated from South Dakota State University in 2023 with a major in agricultural communication and minor in agricultural business. She enjoys connecting with producers and agribusinesses across the region while reporting on all things agriculture.