Saskatchewan cow tests positive for TB in the US

Canada has not encountered an outbreak of bovine TB in a domestic cattle herd since 2018, when 1,000 animals were culled.

By Andrew Joseph, Farms.com; Image: Grigorenko/iStock/Getty Images Plus photo

At a US slaughter, tissue from a heifer tested positive for bovine tuberculosis (TB) and was traced back to a domestic cattle herd in Saskatchewan. The slaughter has now turned up two more cases of the disease.

The Canadian Food Inspection Agency (CFIA) said on June 28, 2023, that it had been notified on February 23, 2023, by the US Department of Agriculture that tissue samples from a slaughtered animal had returned positive on the PCR (polymerase chain reaction) test for bovine TB.

The heifer had been held in a US feedlot since September 2022 after it had been exported from Saskatchewan, according to the CFIA.

Before arriving at the US feedlot, the heifer had spent five months in a Canadian feedlot, where all other contact animals were also destined for slaughter. None were moved to other farms.

The CFIA said that the TB-positive heifer’s herd of origin in Saskatchewan was put under quarantine until testing could be done after spring calving. All animals over six months of age in that herd were tested for the disease last month.

Any animal that showed a response to a standard caudal-fold tuberculin (CFT) test was taken for slaughter and post-mortem exams.

The CFIA said that tissues from suspect animals were then sent to its lab in Ottawa, where PCR tests turned up two additional positive cases of bovine TB on June 19, 2023.

The CFIA said that the new findings "should not affect Canada’s current international status in which all provinces are considered bovine TB-free"—a status that "supports international trade for Canada’s beef industry."

The previous time a bovine TB outbreak occurred was in 2018 in BC, when four cases were found in a herd, leading to the culling of over 1,000 animals. The CFIA said that no definitive source of infection was found.