Montana cow tests positive for brucellosis

BILLINGS, Mont. — Montana officials said Monday that a cow in the Paradise Valley tested positive for brucellosis — a serious livestock disease that had been nearly eradicated among U.S. cattle earlier this year.

The infection means Montana ranchers must undergo an expensive testing program before shipping cattle out of state and will have to increase vaccinations. The state will lose its federal brucellosis-free status until it can demonstrate it has the disease under control.

Brucellosis persists in wild animals including bison and elk in the greater Yellowstone area. It can cause pregnant cows to abort their calves, but transmission to humans is rare.

Consuming animals with the disease is not considered dangerous, state officials said.

In February, the U.S. Department of Agriculture declared all 50 states to be brucellosis-free — the first time that had happened in 74 years.

States lose their brucellosis-free status if the disease is found in more than one herd of cattle in a two-year period. Federal agriculture officials discovered the disease in another herd, near the town of Bridger, in May 2007.

The recent case was discovered late last month during testing of a herd of fewer than 50 cattle in the Paradise Valley south of Livingston. Confirmation came Monday, after a second positive test of the animal at a federal lab in Iowa.

"At this point, this is the only animal we have" with the disease, said state veterinarian Marty Zaluski. "We don't think the disease is widespread in that herd."

The diseased cow has been destroyed, Zaluski said.

An investigation into the source of the infection will focus initially on cattle herds that may have encountered the animal. Those herds will be placed under quarantine until they are tested.

Zaluski said it was "very unlikely" bison from Yellowstone National Park were the source, since none had been documented near the ranch where the disease was found. That leaves another cattle herd, elk or other wildlife as possible vectors of the disease.

Last year's brucellosis outbreak in Montana was linked to elk by state and federal officials, although no conclusive proof was offered.

The downgrading of Montana's brucellosis status is expected within four to eight weeks — or as soon as it can be listed in the federal register.

After that, Montana's livestock producers hoping to export their livestock out of state will be required to test bulls and nonspayed females, 18 months of age or older, 30 days before shipment.

Zaluski said officials from neighboring Wyoming already had contacted Montana to say they wanted testing to begin immediately. More states were expected to follow suit.

State officials declined to name the ranch where the cow originated. They said the owner had been operating under a herd-management plan since spring that required periodic brucellosis testing and vaccinations.

Reacting to Monday's announcement, Gov. Brian Schweitzer blamed the Montana Stockgrowers Association for stopping a management plan the governor says would have saved 95 percent of the state's ranching industry from the sanctions.

He said it was only a matter of time after last summer's case before a second case was found in the state. Last year, Schweitzer floated the idea of asking the federal government to carve out a "split-state" designation for the area around Yellowstone, to insulate the rest of the state were an outbreak to occur near the park.

After the Stockgrowers and Schweitzer sparred over the proposal, the Montana Board of Livestock backed away from the idea.

Schweitzer said the Stockgrowers Association "needs to take full responsibility here today."

Errol Rice, executive vice president of the Stockgrowers, rejected the accusation. He said Schweitzer's idea would have been tough to implement and even then would not have stopped the disease from being carried outside the park by wildlife.

"If the governor wants to talk about things that are proactive, we need to address diseased elk, we need to understand the infection and we need to clean them up," he said.

Efforts to contain brucellosis inside Yellowstone include an aggressive state-federal program to capture and slaughter bison leaving the park during their winter migration.