USA - some quarantined cows could be killed

At least some cows from two Washington state herds quarantined since discovery of a Holstein with mad cow disease will have to be killed, some who may have been exposed to the infection and others because of public fear.


A decision on the first cows to be euthanized will be made very soon, Dr. Ron DeHaven, the Agriculture Department's chief veterinarian, said Friday.


'It would be safe to assume that ... some or all of those animals will need to be sacrificed,' DeHaven said of the two Washington state herds.


Two of the quarantined herds contain calves of the infected Holstein, and mother-to-calf transmission is considered unlikely but can't be ruled out.


One of the calves lives in the mother's own herd in Mabton, Washington, home also to nine other cows that entered the United States from Canada along with the infected Holstein.


The infected mother was born before August 1997, when cow parts were prohibited from cattle feed, the main way that mad cow disease is thought to spread through livestock -- and thus the chief suspect in how she became infected. The question now is how many other cows in that Mabton herd would have eaten pre-1997 feed, too, and thus need to be sacrificed.


But other cows may ultimately be sacrificed, too, DeHaven said.


'Even though we know with a very good degree of certainty that there's no direct disease spread animal to animal, simply being on the same farm there are some public perception issues related to those animals,' he said.


Mad cow disease is a concern because humans can develop a brain-wasting illness, variant Creutzfeldt-Jakob disease, from consuming contaminated beef products. Although 153 people worldwide have contracted that illness, most in Britain, it has never been diagnosed in an American.


A total of 81 animals were believed shipped across the border with the Holstein from Canada in 2001, and USDA has accounted for 11 of them. One is at a dairy farm in Mattawa, Washington, which recently was quarantined, the third herd to be contained.