MONTREAL - Canadian and American agricultural scientists scrambled yesterday to trace the history of a black Angus infected with mad cow disease in Alberta, and ranchers braced for possible economic disaster as Japan, Australia, New Zealand, Taiwan and South Korea joined the United States in banning imports of all Canadian beef and sheep products.
An additional two ranches in the Peace River valley of northern Alberta were put under quarantine, bringing the total of shuttered cattle operations to three, as authorities sought to discover how the cow contracted North America's first case of deadly bovine spongiform encephalopathy in a decade.
Questions were also raised as to why it took Canada 3 1/2 months to determine that the 8-year-old black Angus - slaughtered Jan. 31 after being pronounced too sickly for human consumption - was infected with mad cow disease, the common name for BSE, which is caused by an abnormal protein that destroys nervous system tissue.
If the disease is shown to have been spread through feed grains or veterinary medicines in North America, the result might be the near shutdown of one of Canada's most important agricultural sectors and the destruction of millions of cows, as occurred in Great Britain during that country's calamitous outbreak of mad cow disease. Humans who eat infected meat can catch a rare but fatal variant affliction known as Creutzfeldt-Jakob disease, which has killed about 100 people since 1996, mainly in Britain.
Prime Minister Jean Chretien sought to quell panic among cattle farmers and feed lot operators from Prince Edward Island to British Columbia, and to soothe mounting fear among consumers that Canadian beef might be hazardous to their health.
"If it is one herd, it is not the same as if it is spread," he told reporters in Ottawa shortly before eating an Alberta sirloin steak, grilled medium, at a downtown restaurant in front of news cameras. "So we hope and we pray ... that it is [just] one cow in one herd."
Ranchers expressed similar hope that the disease will prove to be limited to the single animal whose tissue tested positive for mad cow disease in a British veterinary lab Tuesday, resulting in a U.S. ban on Canadian beef imports that will probably last weeks and could become permanent if the disease appears to have spread to other herds.
"Right now, we're pretty much holding our breath and waiting for the scientists to do the research that has to be done," said Erik Butters, a longtime cattle rancher in Cochrane, Alberta.
Canadian beef is sold in supermarkets and fast-food franchises across the United States. Americans eat more than 70 percent of Canada's exported beef, worth more than $2.5 billion, much of it from Alberta. Canada is the world's third-largest beef producer, and confirmation of the most-dreaded bovine disease appearing in Alberta has sent shock waves through the North American cattle industry.
"Since our export markets are absolutely critical, this could be devastating for our industry," Butters said in a telephone interview. "We think we have one of the best animal health systems in the world, so that gives us some reassurance. But there is not a rancher in Canada who doesn't feel under a black cloud. We know what this disease did to Britain."
Mad cow disease, a still little-understood veterinary ailment for which there is no vaccine or cure, has an incubation period usually lasting from three to six years but sometimes stretching to a decade. That is why Canadian health and agricultural authorities are so focused on determining the origin of the black Angus, which was brought to the Alberta ranch three years ago, before Canada made it mandatory to keep extensive computerized records on the origins of all beef cows.
The U.S. Department of Agriculture dispatched an animal health research team to Alberta yesterday, and U.S. Custom Service agents turned back truckloads of garbage from Toronto - which relies on Michigan landfills - over concern that they might hold contaminated meat.
Largely because of the North American Free Trade Agreement, American and Canadian ranches, feed lots, and beef marketers are so closely integrated that it is nearly impossible to tell where one nation's cattle industry begins and the other ends, with thousands of live cows and millions of dollars' worth of meat transported across the border every day.
The only other case of mad cow disease in Canada, in 1993, was in an animal imported from Britain. Because the disease apparently does not spread from cow to cow, but is transmitted, in ways not fully understood, through feed grain or veterinary drugs containing products derived from rendered cows, it is critical to learn where the black Angus came from because it may have contracted the disease before reaching its last ranch in Alberta. Other infected cows could appear at other ranches.
"I'm sorry to say this, but I think this is just the beginning," Margaret Hayden, senior veterinary drug evaluator for Health Canada, the national health ministry, told the Canadian Broadcasting Corporation.
As a precautionary step, the Canadian Ministry of Agriculture ordered the slaughter and testing of the remaining 149 cows at the ranch near Fairview, Alberta. At least two other Alberta ranches where the black Angus may have stayed were placed under strict quarantine yesterday.
In Britain, the disease is now believed to have been spread by feed grains fortified with protein products made from bone meal and spinal cord or brain tissue from slaughtered cows. The use of such treated grain has been banned in Canada and the United States since 1997, but there are still many animals alive that were raised on such treated grain - and some might only now be succumbing to a disease they contracted in the mid-1990s.