Canada reported its first case of mad cow disease in a decade on Tuesday, sending shock waves through the North American food industry.
A cow in Alberta, Canada's top cattle-producing province and a major beef exporter to the US, tested positive on Friday for brain-wasting bovine spongiform encephalopathy (BSE), or mad cow disease, in a test conducted after it was slaughtered last winter, government officials said.
"The actual test was taken on Jan. 31 from a cow in Fairview, Alberta," an official with the Canadian Beef Export Federation said. "It's just one isolated case of an 8-year-old cow."
But the report sent a major chill through the continent's economy, triggering a ban on Canadian beef and sparking a sell-off in cattle futures and food-related stocks such as hamburger giant McDonald's and Wendy's International. Shares of Tyson Foods, which has a large beef-packing plant in Alberta, also dropped in New York.
The animal was not processed and its northern Alberta herd of 150 animals will be slaughtered, as will any other found to be affected, Canadian Agriculture Minister Lyle Vanclief told a nationally televised news conference in the Alberta capital of Edmonton. Vanclief said he did not know the cow's origin.
"The investigation to date has indicated the animal in question was sent to a rendering plant after slaughter. I want to stress that the animal did not go into the food chain," he said.
Other herds had yet to be quarantined.
"We've only been investigating this for about 24 hours," a government scientist said.
The US quickly slapped a temporary ban on imports of Canadian cattle, sheep and goats as well as meat and other products. But the US Agriculture Department said the threat of transmitting the disease to animals in the US was very low and it planned no further measures.
Japan and South Korea, the third and fourth largest markets for Canada's beef exports, issued similar importation bans, with South Korea also banning the importation of Canadian dairy products.
In Taiwan, the Council of Agriculture said yesterday it has decided to temporarily ban imports of stud cattle, beef and other related products of cattle, sheep and goats from Canada.
Yesterday, authorities in Australia said they had tracked down all Canadian cattle imported into Australia and banned further imports. Australia only imports breeding cattle from Canada and does not buy any meat products.
Canada's only other case of mad cow disease was in 1993, but that particular animal was imported from Britain, where the disease led to the slaughter of 3.7 million cattle and a US ban on British imports. Its carcass was destroyed, as was its herd.
The new case is a major blow to Alberta, where about 5.5 million cattle dot the landscape, outnumbering people by almost 2.5 million. The western province accounts for nearly 60 percent of Canada's beef production, providing C$3.8 billion (US$2.8 billion) in annual farm cash receipts.
Mad cow disease first erupted in Britain in 1986, and is thought to have spread through cow feed made with protein and bone meal from mammals.
The human form of mad cow disease is Creutzfeldt-Jakob disease, which causes paralysis and death. Scientists believe humans are able to develop new variants of Creutzfeldt-Jakob when they eat meat from infected animals.
Both Canada and the US outlawed the feeding of meat and bone meal to cattle, sheep and goats in 1997, a rule believed to be the main defense against the disease.