CHEYENNE – State and federal agriculture officials began taking blood samples on Wednesday from a western Wyoming cattle herd infected with brucellosis, the first step toward figuring out whether the state will lose its federal status as brucellosis-free.
The Wyoming State Veterinary Laboratory this week confirmed positive brucellosis tests for two cows from the herd of black Angus cattle near Daniel, a Sublette County town about 100 miles southeast of Yellowstone National Park.
The Wyoming Game and Fish Department said brucellosis is known to exist in wildlife in the Daniel area, as in much of the greater Yellowstone ecosystem. The disease, which can cause pregnant cows to abort their young, can be introduced by to livestock by wild animals such as elk or bison, or transmitted among cattle.
State Veterinarian Walter Cook said vets from his office and the USDA Animal and Plant Health Inspection Service were drawing blood from half of the herd near Daniel. The samples were to be tested at the state lab in Laramie, and results could be available by Thursday.
The second half of the Daniel herd will be tested on Monday, Cook said. Then the vets will test other herds that have been in contact with the infected herd, possibly through exposure in situations such as breeding, at auction or grazing in an adjacent pasture. State law prevents officials from naming ranchers with infected herds.
Cook said he didn’t know what the odds were of finding more infections.
“That’s why we need to get this done,” he said. “For all we know, the infection may have originated in a different cattle herd and may have spread to this herd. Those are some of the questions that we’re going to try to answer.”
With vaccination and monitoring policies, agricultural officials had largely eradicated the disease from livestock in the United States, but that changed this month. Wyoming’s detection came on the heels of the discovery of an outbreak on a Montana ranch about 30 miles north of Yellowstone, costing the state its federal brucellosis-free status.
“I don’t want to end up where the state of Montana is and lose our brucellosis-free status,” Gov. Dave Freudenthal said at a Wednesday press conference. “But we’ve worked our way through that problem before, and we’ll work our way through it again.”
Nearly 100 people, most of them Sublette County ranchers, showed up for a Wyoming Livestock Board meeting on the brucellosis outbreak in Pinedale on Tuesday night, radio station KPIN-FM reported.
While brucellosis vaccinations have been required in Wyoming decades, many ranchers in the crowd said they want to return to the “Strain 19” vaccine and discontinue use of the “RB51” vaccine. They said the Strain 19 vaccine, which was discontinued in the mid-1990s, was more effective than RB51.
“Many of the ranchers think (Strain 19) offers better protection, particularly over the long run,” Cook said Wednesday. “Studies show that RB51 offers the same strength of protection, but those were short-term studies. Whether it offers comparable protection six or eight years down the line, we don’t know.”
Freudenthal said the larger question is whether the federal government will provide enough funding to develop a reliable vaccine.
“You’re always going to have commingling between livestock and wildlife,” Freudenthal said. “The question is trying to use our scientific knowledge, our advance in scientific knowledge, so that you can address this issue.”
Wyoming has 60 days to carry out its epidemiological probe, Cook said. The state will retain its brucellosis-free status if investigators find no other infected herds and the Daniel rancher with the infected cows agrees to slaughter his entire herd. Wyoming would then be on a two-year watch, during which time the federal government would revoke the state’s brucellosis-free status if another infection occurred.