A potential case of mad cow disease has been identified in an Alberta cow, officials with the Canadian Food Inspection Agency announced Monday.

The four-year-old dairy cow died on an Edmonton-area farm and did not enter human or animal food systems.

The Canadian Food Inspection Agency is launching an exhaustive testing process to determine how the cow was infected.
(CBC)

If confirmed, the cow would be Canada's seventh case of BSE.

The animal was born after 1997, when Canada imposed a ban on the type of feed associated with bovine spongiform encephalopathy.

The agency's senior veterinarian, George Luterbach, said the cow could have been infected by cattle feed that had accidentally mixed with another animal's feed in a bin.

Cattle are most likely to get BSE within the first year of life, he said.

"We are interested in determining which cattle [were] born within a year of this positive animal and consumed the same contaminated feed. We will identify those animals with the goal of eliminating them from the national herd," he said.

The agency has quarantined the farm and is looking into whether the cow, which was close to giving birth when it died, had any other offspring.

The case comes a week after final test results confirmed a diagnosis of BSE in a cow from Manitoba, although that cow was born before 1997.

The findings should not raise alarm in the United States, said Luterbach.

"The position of the U.S. Department of Agriculture is that Canada has a sound and robust program."

Samples have been sent to the National Centre for Foreign Animal Disease in Winnipeg for testing. Preliminary screening tests could not rule out BSE.

Tightening the rules

Since 1997, protein-based tissues from the skulls, brains, nerves, eyes, spinal cords and bones of older cattle have been banned from cattle and ruminant feed manufactured or sold in Canada because of their role in passing on the disease.

Last month, the agency announced it was cracking down even further on potential ways of spreading BSE. A year from now, cattle tissues that could transmit mad-cow disease will no longer be allowed in pet foods, chicken feed and fertilizer under new federal rules.

Luterbach predicts that BSE will be eradicated from Canada's herd over the next 10 to 15 years thanks to those measures.

Alberta home to 2003 BSE case

The discovery of BSE in an Alberta cow in May 2003 threw the country's cattle industry into chaos. Many countries closed their borders to imports of Canadian cows or beef in the wake of the discovery.

Since then, the agency has tested 115,000 cattle and reported five more cases of the disease in Canada. Another infected cow found on a U.S. farm had come from Canada, according to the Canadian Food Inspection Agency.

Internationally, BSE has been linked to a deadly type of Creutzfeldt-Jakob disease among humans who have eaten certain types of tissues from infected cows.

with files from Canadian Press