Anthrax kills beef cattle in Santa Clara

Eric Brazil, Chronicle Staff Writer

Tuesday, October 30, 2001

Anthrax has killed 21 beef cattle on a southern Santa Clara County ranch, the California Department of Food and Agriculture said yesterday.

It is the worst outbreak of anthrax in California livestock in 17 years.

State veterinarian Dr. Richard Breitmeyer said the first indication that some of the cattle in the herd were ill had come Oct. 20, but his office was only informed of the seriousness of the outbreak on Friday.

The first veterinarian on the scene did not diagnose anthrax -- that was done by microbiologists at the University of California at Davis, Breitmeyer said.

State and Santa Clara County Health and Agriculture department officials declined to disclose the name of the cattle's owners or the ranch.

Breitmeyer said that there was no apparent connection between the anthrax terrorist attacks on the East Coast and the deaths of the cows. However, he said, "because of the heightened awareness, we contacted the FBI and transported the bacteria culture to them so they can have it to make sure it is our garden variety anthrax."

The carcasses of the dead cattle have been buried, and 120 healthy animals in the herd have been corraled and quarantined for 60 days, and vaccinated against the disease. They are being fed and are not grazing, Breitmeyer said.

Anthrax was once a common scourge of cattle throughout the West, and still claims hundreds of head annually in Texas. But a rigorous vaccination regimen practiced by California ranchers has virtually eliminated it as a major threat to the state's herds.

Because the ranch where the cattle died did not have a history of anthrax, the herd had not been vaccinated, Breitmeyer said.

"It was pretty dry, and the (cattle) were obviously grazing pretty close to the ground, and they must have ingested a pretty good dose of anthrax," he said.

The Santa Clara County deaths are the most serious anthrax outbreak in California since 1984, when the disease killed 135 sheep and 43 cattle pastured on the Carrizo Plains of San Luis Obispo County.

Although anthrax spores are ubiquitous in the ground in Northern California's rangeland, just nine confirmed cases had been reported since 1991.

Santa Clara County Agricultural Commissioner Greg VanWassenhove said that the ranch affected by the outbreak was a cow-calf operation, with range bulls, "and some of each died."

Dr. Sharon Hietala, a pathologist with UC Davis' animal disease diagnostic laboratory, said vaccinating healthy members of the herd was done to prevent further exposures to anthrax bacteria.

Dr. Rance LeFebvre, a UC Davis microbiologist and anthrax expert who teaches a course on bioterrorism, said that as a practical matter, "if they get the (healthy) animals out of the field they've been grazing in, the risk is gone. . . . Chances are, their immune system will kick in in a couple of weeks."

Anthrax vaccine for livestock uses a live organism as its immunizing agent and is not considered suitable for use on humans.

-- PHO (owennos@bigfoot.com), October 30, 2001