Canadian mad cow probe widens

Thirteen cattle herds placed under quarantine

Story Tools VIDEO Canadian authorities announce the discovery of a single case of mad cow disease. CNN's Greg Clarkin reports (May 20) PLAY VIDEO RELATED • Mad cow disease reported in Canada  • Fear, mystery of mad cow disease  HEALTH LIBRARY • Health Library  • Men's Health  • Women's Health  • Care for the whole family  HUMAN THREAT Mad cow disease was first reported in the United Kingdom in 1986, peaking in 1993 with almost 1,000 new cases per week.  In 1996, variant Creutzfeldt-Jakob Disease (vCJD) was detected in humans and linked to the mad cow epidemic. Eating contaminated meat and cattle products is presumed to be the cause. Both are fatal brain diseases with unusually long incubation periods, often lasting years. To date, no case of mad cow disease has been identified in the United States. As of April 2, 2002, a total of 125 cases of vCJD had been reported in the world: 117 from the United Kingdom, six from France, and one each from Ireland and Italy. Source: CDC

OTTAWA, Canada (CNN) -- Canadian health officials trying to track the comings and goings of an 8-year-old cow infected with mad cow disease said Friday they have quarantined 13 herds in three provinces that have some connection to the cow.

The sickly cow was pulled from a production line and killed in January at a slaughterhouse in Alberta. Because its meat was not mixed with meat headed for grocery stores and restaurants, health officials said they did not test the cow for bovine spongiform encephalopathy (BSE) -- the scientific name for mad cow disease -- until last week.

The cow's carcass was rendered in January and used as a supplement for chicken feed, health officials said. Since then, health officials have rushed to trace both the eight-year history of the cow and the destination of the chicken feed.

Mad cow disease is a progressive, fatal disease of the nervous system of cattle. No U.S. cows have tested positive for the disease, which was first recognized in the United Kingdom in 1986.

The fatal brain-wasting disease is believed to be spread through contaminated cattle food and cannot be passed from cow to cow. A human disease -- variant Creutzfeldt-Jakob disease (vCJD) -- was identified in 1996 and linked to eating mad cow-contaminated meat and cattle products.

Officials have said all week that they think they have contained the infection. But news that Canada had its first case of BSE in 10 years prompted many of the countries that import Canadian beef to temporarily issue a ban. Among the countries is the United States, Canada's largest beef customer.

Dr. Brian Evans, the Canadian Food Inspection Agency's chief veterinary officer, said Friday that eight of the quarantined herds are in Alberta, two in Saskatchewan and three in British Columbia. All of those are western Canadian provinces, the home of most of Canada's cattle industry. When processing, transportation, retail and food service is considered, Canada's cattle farmers are part of a $26 billion industry, according to the Canadian Cattleman's Association.

Seven of the herds were quarantined because health officials think the cow lived among them at some point. Three of the quarantined herds contained cows that were offspring of the infected cow, and three herds in British Columbia had some connection to the chicken feed made from the cow's carcass, Evans said.

Evans said officials are trying to find the farm where the diseased cow was born. Canada implemented a cattle identification system a few years ago, but officials say it started too late to help with this investigation.

Health officials said they are cross-referencing records from farmers, truckers and numerous buyers and sellers of cattle to piece together a timeline for the cow.

Canada has banned the feeding of protein from ruminants -- animals with four stomachs -- to other ruminants since 1996, but that feed can be given to pigs and chickens, animals not believed to be able to contract BSE.

Aside from visits from provincial and national health inspectors, it is left to the person feeding the cattle to make sure such feed is not fed to cows, Evans said.

The owner of the Saskatchewan farm that is one possible birthplace of the diseased cow said Thursday that feed given to his herd might have been the source of the BSE.

"You live with it and you go on as far as I'm concerned," said Mel McCrea, owner of the Anchor R farm. "If there's something wrong with the feed, with the protein we bought, God help the whole system."

On Friday, U.S. Sen. Byron Dorgan criticized the fact that it took four months for the diseased cow's brain to be tested. The North Dakota Democrat is a member of the Senate Agriculture Appropriations subcommittee.

"I don't want to make more of this or less of this than warranted," he said. "But a severed cow head [sitting] on a cool shelf for months before it's tested, is not a good system."

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