OTTAWA, Ontario – Tissue samples taken in October 2018 from a beef cow at slaughter revealed a strain of bovine tuberculosis (TB) that is distinct from any previous cases of the disease reported in Canada, the Canadian Food Inspection Agency (CFIA) reported.

Animal health officials traced animals from the infected herd to parts of British Columbia, Alberta and Saskatchewan. Movement controls were placed on approximately 18,000 head across 25 premises. Investigators will continue to identify the previous movements of animals that entered the herd within the past five years, CFIA said, which could result in fluctuations in the number of herds under movement controls.

“The number of movement controls will fluctuate as the investigation progresses, with controls being added as new trace-out locations are identified and lifted when animals test negative for the disease.” The agency said.

To date, four cases of the mystery strain have been found in one herd in the southern interior of British Columbia. The case count includes the beef cow that was slaughtered in October, according to CFIA. A post-mortem examination of that animal revealed the presence of “granulomatous lesions in the mediastinal lymph nodes, lungs and liver.” The CFIA’s Ottawa Laboratory — Fallowfield conducted testing of the tissue samples from the animal and reported the findings.

The agency noted that none of the infected animals entered the food chain and posed no risk to Canada’s food supply or to human health. But, “as testing of the index herd continues, additional cases may be detected,” CFIA said.