Diseased Cow Traced to Canada, U.S. Says

WASHINGTON —  Federal agriculture officials said Saturday that they had traced a Holstein infected with “mad cow” disease in south-central Washington state to a herd of 74 dairy cows brought to the United States more than two years ago from Alberta, Canada.

“That’s most likely where she became infected,” said Dr. W. Ron DeHaven, chief veterinarian for the Department of Agriculture, who added that officials were working with cattlemen to locate the other 73 cows.

However, a disagreement flared between the Americans and Canadians regarding the age of the Holstein -- and in which of the two countries the animal most likely acquired “mad cow” disease.

Canadian authorities said their records showed the Holstein was about 6 1/2 years old, while the U.S. officials, citing documentation maintained by owners of the cow, placed the age at closer to 4 years.

The cow’s age is important because in 1997 both nations banned cattle feed that contains bone meal from other animals, which is how “mad cow” disease has commonly been spread. If the infected animal was closer to 4 years old, it would strongly indicate that the Holstein ingested feed that had been outlawed several years earlier.

Dr. Brian Evans, chief veterinary officer of the Canadian Food Inspection Agency, said Saturday that the infected cow’s origins had not been confirmed. Addressing reporters in Ottawa, he cautioned against “a premature conclusion that the definitive animal or definitive birthplace has been located.” Evans added, “I don’t think anybody should read this as tarnishing Canada as a ‘mad cow’ haven.”

In May, a single cow in Alberta was found to have “mad cow” disease, and Canadian authorities have yet to identify the source of its infection.

Using DNA testing, U.S. agriculture officials hope to conclusively establish the Holstein’s age, perhaps within the next week.

While the U.S. officials played down any risk to consumers, they also announced that they would continue recalling from stores in California, Nevada, Oregon and Washington any as-yet unsold beef from the infected cow and other cattle that were slaughtered and processed on Dec. 9 at a plant in Moses Lake, Wash.

“We will leave no stone unturned in this investigation,” DeHaven said.

“Mad cow” disease is a public health concern because humans who eat infected beef can develop a brain-wasting disorder called variant Creutzfeldt-Jakob disease. The disease is always fatal. In Britain, 143 people died after “mad cow” disease surfaced in the 1980s.

DeHaven and other officials did not immediately identify the stores that may have purchased the beef subject to the ongoing recall. They said the recall applied to about 10,000 pounds of meat taken from 20 animals, including the infected cow, that were slaughtered at the plant that day.

The officials said that sellers of the meat began notifying affected retail stores on Christmas Eve.

“I expect that over the next several days we will start to get a handle on the exact amount that is being retrieved,” said Dr. Ken Peterson of the Department of Agriculture’s Food Safety and Inspection Service. “Not all of the meat, but much of it, was ground into either ground beef or ground beef patties. Those are fresh products, so it is entirely possible that some of the meat has at least been purchased. Whether it’s been consumed, we will find out.”

Both DeHaven and Peterson emphasized that they believe the chance is low that any consumer would contract the human variant of “mad cow” disease from the infected Holstein because, they said, the beef that was processed did not include brain or spinal-cord material.

And they referred to available scientific evidence, which indicates that “mad cow” disease is not transmitted to humans through milk or other dairy products.

DeHaven said “the infectious agent goes primarily to central nervous system tissues,” such as the spinal cord or brain. The U.S. officials have said that the packing plant in Washington state kept the meat separate from the spinal and brain material.

DeHaven said U.S. officials believe the infected Holstein, part of a herd of 74 dairy cows, entered the United States from Canada in August 2001 at Eastport, Idaho.

“These animals were all dairy cattle and entered the U.S. only about 2 or 2 1/2 years ago, so most of them are still likely alive,” DeHaven said.

Whether or not most of the animals remain alive would depend largely on their age when they entered the country. Cows typically begin calving, and then producing milk, when they are 24 to 26 months old. The cows often are removed from herds at age 4 or 5 for slaughter, according to Dr. James Cullor, a veterinarian who is director of the UC Davis Veterinary Medical Teaching and Research Center in Tulare.

“The origin of [the infected cow’s] birthplace and the confirmation of her age is going to help trace the [suspect] feed source,” Cullor said.

Because U.S. officials have not yet confirmed where or how the infected Holstein contracted “mad cow” disease, also known as bovine spongiform encephalopathy, or BSE, they have quarantined a herd of calves -- including a male born less than a month ago to the Holstein -- at a farm in Sunnyside, Wash. Many of the calves most likely will be killed as a preventive measure.

“Since the calf [from the Holstein] was not tagged, all bull calves at the Sunnyside premises under 30 days of age will likely be depopulated,” the Agriculture Department said in a written statement. Associated Press reported that the herd has about 400 calves.

By Saturday, more than two dozen countries, including tiny Kuwait, had banned U.S. beef in response to the single finding of “mad cow” disease in Washington state. Unless confidence is restored, U.S. cattlemen stand to lose billions of dollars a year in exports and domestic sales.

U.S. agriculture officials Saturday traveled to Japan, a leading importer of American beef, to explain the steps they are taking to safeguard American cattle.

Times staff writer Maggie Farley contributed to this report.