WASHINGTON (Dow Jones)-Federal officials said Thursday that they now know the latest cow found in the U.S. with mad- cow disease was 10 years and seven months old and came from a dairy farm in Tulare County, Calif., giving investigators new pieces of the puzzle as they try to trace back the animal's origins.
The cow had been sent from the dairy to a rendering operation where it was tested for the disease as part of the Department of Agriculture's routine monitoring.
Investigators need to know how old the cow was when it died as well as where it was born to find out if it sired any offspring as well as locate herd mates from early on in its life, USDA Chief Veterinarian John Clifford said Wednesday.
If the investigators find any offspring or early herd mates, it will purchase them and take them off the market, Clifford said.
It's believed a cow with mad-cow disease, also known as bovine spongiform encephalopathy or BSE, may be able to pass the fatal brain-wasting disease to offspring, Clifford said.
"It's important to reiterate that [the California dairy cow] was never presented for slaughter for human consumption, did not enter the food supply channels and at no time presented any risk to human health," the USDA said in the Thursday announcement.
It is the fourth cow ever found with BSE in the U.S. and the first since 2006. The disease can be transmitted to humans through the consumption of tainted meat.
The USDA didn't elaborate on the cow's symptoms other than to say it was "humanely euthanized after it developed lameness and became recumbent."
Routine testing at a transfer facility showed the dead Holstein, which was destined for a rendering plant, had mad cow disease, or bovine spongiform encephalopathy. The results were announced Tuesday.
Animals at high risk for the disease include those with symptoms of neurological disease, "downer" animals at slaughterhouses, animals that die at dairies or cattle ranches for unknown reasons, and cows more than 2 1/2 years old, because BSE occurs in older cows.
U.S. health officials say there is no risk to the food supply. The California cow was never destined for the meat market, and it developed "atypical" BSE from a random mutation, something that scientists know happens occasionally. Somehow, a protein the body normally harbors folds into an abnormal shape called a prion, setting off a chain reaction of misfolds that eventually kills brain cells.
In other countries, BSE's spread through herds was blamed on making cattle feed using recycled meat and bone meal from infected cows, so the U.S. has long banned feed containing such material.