Canada's frantic search for more cases of mad cow disease spread beyond its biggest cattle region on Thursday, as inspectors sealed off several farms and more countries banned Canadian beef.
The crisis, sparked by the revelation on Tuesday that one cow in the big beef-producing province of Alberta tested positive for the deadly brain-wasting disease, led officials to quarantine nine farms, two of them in the neighboring Saskatchewan, where the diseased cow may have been born.
Inspectors have so far found no other cases, Claude Lavigne of the Canadian Food Inspection Agency said as the country's export-oriented beef industry ground nearly to a halt.
One quarantined herd is the one in which the cow with bovine spongiform encephalopathy (BSE), or mad cow disease, was found, five are linked to where it was earlier in its life and three are linked to its possible offspring.
"The ongoing investigation into the cause of this incident of BSE is now focusing on confirmation of the cow's birthplace and the history of the feeding practices and sources of animal feed for this cow," Lavigne said.
At stake is the C$4 billion (US$2.9 billion) beef industry in Alberta, where cattle ranching has been a way of life for more than a century, as well as North America's faith in the safety of its food supply. Last year, Alberta shipped more than half a million live cattle to the US.
Using bills of lading and records of livestock brands, and tapping into a new cattle database, investigators are tracing the origin of the animal -- Canada's first mad cow case in a decade -- and trying to find out if any others are infected.
Despite the tracking effort and repeated assurances by health officials and politicians that the beef is safe, Russia, Singapore and Indonesia joined the US, Japan and other countries in temporarily banning Canadian shipments.
The scare has forced the beef industry in Alberta and other parts of Canada to its knees, with packing plants winding down and normally bustling auction markets quiet.
Canadian packers and live cattle exporters have been losing at least C$11 million a day in revenues with shipments backed up at the border, said Ted Haney, president of the Canadian Beef Export Federation.
The BSE-afflicted cow, from a farm near the village of Wanham in northern Alberta, was tested after it was slaughtered in late January. But test results were not available until last week.
Inspectors told Trevor McCrea, a farmer from Baldwinton, Saskatchewan, the cow may have come from his family's breeding operation. The herd is now in isolation.
The herds now under quarantine represent a minuscule fraction of the 90,000 across the country.
At his farm near Wanham, the affected cow's owner said late Thursday he did not believe it contracted BSE there.