Brucellosis confirmed in Montana herd

By SCOTT McMILLION Chronicle Staff Writer

It's finally happened. Brucellosis was confirmed this week in domestic cattle in Montana, in a herd near Bridger.

Since 1985, the state's beef herds have been certified as free of the disease, which causes cattle to abort their first calf after infection.

Fear of brucellosis drives most of Montana's controversial efforts to limit bison moving into the state from Yellowstone National Park. However, Gov. Brian Schweitzer said Friday that it doesn't appear the outbreak is linked to bison.

“These are not cattle that ever commingled with buffalo,” he said by telephone Friday.

The outbreak affects seven cows traced to a ranch in Bridger, a small town south of Laurel and far from any Yellowstone bison.

Schweitzer said some of the infected cattle might have spent time in the Emigrant area in Paradise Valley, about 25 miles from the park's northern boundary.

“That still doesn't mean buffalo” are the source of the disease, he said. “Buffalo don't make it to Emigrant.”

A small percentage of elk also carry brucellosis, and elk wander more widely than bison. Officials in Wyoming and Idaho, which lost their brucellosis-free status in recent years, said mixing with infected elk is a likely source of the domestic cattle infections in Montana.

In Wyoming, four herds near Yellowstone tested positive in 2004, but the state regained its brucellosis-free status in 2006. Idaho lost its brucellosis-free status in 2005. The status has not been regained.

The herds in Wyoming and Idaho “most likely were infected by elk,” said Teresa Howes, spokeswoman for the U.S. Animal and Plant Health Inspection Services, which oversees the federal brucellosis-eradication program.

One infected herd does not mean the entire state loses its brucellosis-free status. But if a second herd tests positive, every rancher in Montana will face expensive testing and time-consuming restrictions when exporting cattle.

Though once considered a significant public health threat because it spread through unpasteurized milk, brucellosis is now considered mostly an animal disease.

For Montana to retain its brucellosis-free status, the infected herd must be quarantined and depopulated within 60 days, and an investigation must confirm that the disease has not spread.

Dennis McDonald, past president of the Montana Cattlemen's Association, said guessing at the source would be “pure speculation.” He also called the existing management plan inadequate.

The disease was first noted in the state when a load of 51 cattle from mixed sources was shipped from Baker, in far-eastern Montana, to Iowa. The cattle were tested for the disease May 1, and one tested positive in preliminary tests, Schweitzer spokeswoman Sara Elliot said Friday.

After the test was confirmed, the cow was euthanized at Iowa State University on May 8.

Investigators then traced the cattle movements to a 301-head herd in Bridger, where more testing was done May 16. The Montana Department of Livestock Diagnostic Laboratory in Bozeman confirmed that six cattle from that herd had the disease.

For the past couple of years, Schweitzer has been calling for a new brucellosis plan near Yellowstone. His plan would involve greater disease-control efforts by the National Park Service and a zone near the park in which all cattle entering or leaving would be tested. The plan also calls for the federal government to compensate ranchers who voluntarily stop grazing in that zone.

And, if two herds become infected, it would not mean the loss of disease-free status for all ranches in the state.

“I just hope we can get people to start listening to us,” Schweitzer said. “We're going to make the best of it. Wyoming and Idaho went first. Now I know how they felt."

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