USDA probes possible third case of mad cow disease

WASHINGTON (Reuters) – A 12-year-old animal suspected of
having mad cow disease will be retested by animal health
laboratories in Britain and Iowa for confirmation of what would
be America’s third case, the U.S. Agriculture Department said
on Wednesday.

Final test results are expected early next week.

USDA Chief Veterinarian John Clifford said the suspect
animal, which was destroyed after having trouble giving birth
in April, produced an inconclusive result in an initial round
of testing for the brain-wasting disease.

“USDA is conducting further testing at the National
Veterinary Services Laboratories in Ames, Iowa, in consultation
with experts from the international reference laboratory in
Weybridge, England,” he told reporters.

“We are also sending samples from this animal to the
Weybridge laboratory for further testing. It is important to
note that this animal poses no threat to our food supply
because it did not enter the human food or animal feed chains,”
Clifford said.

Clifford described the suspect animal as U.S.-born, but
refused to identify where it had lived.

America’s second case of mad cow disease — its first in a
native animal — was confirmed last month. That animal, a
12-year-old Texas cow, tested positive for the brain wasting
disease after initially returning inconclusive results.

VET “FORGOT” TO SEND SAMPLE

The latest case also involves confusion over test
procedures.

A local veterinarian who submitted the cow’s brain sample
to the USDA first treated it with a preservative, making it
impossible to conduct a sophisticated test known as the Western
blot, Clifford said. USDA scientists can still conduct an
immunohistochemistry (IHC) test, but they cannot use the
Western blot test for a comparison.

In addition, the veterinarian obtained the brain sample in
April but did not send it to the USDA until a few days ago,
Clifford said, because he “simply forgot to send it in.”

The U.S. cattle industry said the suspect cow never entered
the human food supply.

“It is important to remember that the U.S. government and
the beef industry have put science-based precautions in place
over the past 15 years to ensure our beef remains safe from
BSE,” said Terry Stokes, chief executive of the national
Cattlemen’s Beef Association.

Meanwhile, the suspect animal’s herd has not been
quarantined, Clifford said.

“We do not have a hold order on the location at this time.
We have not called this a case of BSE. At the time that we
would do that it would be appropriate for us to put a hold
order only for a length of time for us to look at other animals
of interest that may be in that herd.”

The first case of bovine spongiform encephalopathy (BSE) or
mad cow disease discovered in the United States was in December
2003, in a Washington state dairy cow imported from Canada. In
response, the USDA adopted several new safeguards including an
increase in testing U.S. cattle for the disease, a ban on using
crippled or downer cattle in the human food supply, and a ban
on using the brain, eyes and small intestines of older cattle
in human food.

That case prompted major beef trading partners like Japan,
South Korea and Taiwan to close their borders, shutting off
billions of dollars worth of U.S. beef imports.

The latest incidents come as Bush administration officials
had started to make optimistic comments about persuading those
countries to start buying U.S. beef once more.

Clifford said he did not think the new investigation would
affect trade negotiations.

“Japan has had 20 cases of BSE,” he said. “We would hope
this would not have any impact on our negotiations. Both our
animals were born prior to the feed ban.”

The USDA also recently won its appeal to start imports of
live young Canadian cattle for the first time in two years,
arguing against protests from ranchers and consumer groups that
Canada’s safeguards against the disease were adequate.