The sole cow infected with mad cow disease in Washington caused Canada to ban all beef from the entire US. However it appears now that the cow in question originated in Canada. Records show that the cow and 73 others came from Alberta, Canada 2 years ago.
The cow died as a member of the herd at the Sunny Dene Ranch in Mabton, Washington. Mabton is a town in the southern area of Washington state, by the Oregon border. But the cow had only been with that herd since October 2001, and officials do not believe it was ever fed cow brains while with Sunny Dene. The way that cows contract mad cow disease is to be fed the brains of other, infected cows. Feeding cow parts to other cows has been illegal in the US since 1997.
With the Sunny Dene herd being clean, investigators then began to work backwards to see where this cow came from. A Washington Post reporter was told by a vet on the case that the cow in question "didn't spend her whole life in the state of Washington". Many other sources report that, with the beef herds growing rapidly in the past few years in this region of the US, many farmers brought in cattle from Canada to fill out their herds. Investigators tracked the cow down to a shipment from Alberta, Canada.
Canadian officials had found a cow from Alberta with mad cow disease in January 2003. Cow-meat feed was banned 6 years ago, but the cow brought from Canada to the US was 6 1/2 years old. So it could have been fed the bad feed in its first 6 months of life. It takes 4 or 5 years for full incubation of the disease to occur.
US butcher shops do not use the brain or the spinal area of a cow due to federal regulations. These two areas are the ones that can possibly carry mad cow disease. The recall of the beef is an additional safety precaution, but the infectious parts of the cow in question were never part of the food supply.
UPDATE: While many felt this was the beginning of an epidemic of mad cow disease, there really have been no major outbreaks at all since this case.
Mad Cow Disease Found in Washington
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