State could keep class-free status under interim USDA rules

Expanding a designated surveillance area that requires additional testing of cattle for brucellosis could help Wyoming maintain its federal disease status, a Powell veterinarian said.

State livestock officials have proposed adding eastern Park County to the current “designated surveillance area.” Wyoming’s DSA now covers Park County west of Wyo. 120 as well as Teton and Sublette counties, western Fremont County and northern Lincoln County.

“It seems to be working for us, in doing this test area,” said Lyle Bischoff of Powell Veterinary Services.

Bischoff supports expanding the test area, as proposed by officials from the Wyoming Livestock Board, to encompass all of Park County. Currently, female cattle of reproductive age in most cases must undergo additional testing for brucellosis before they are sold or moved out of the area.

The current designated surveillance area requirements do have some exceptions, Bischoff said, including waiving those extra tests for cattle headed directly to slaughter or to be fed at a feedlot followed by slaughter.

The current DSA boundary, Wyo. 120, is just an “imaginary” artificial line, Bischoff said.

“What’s to say that elk aren’t going to cross that highway?” he asked. Elk are already “all over Heart Mountain” and migrate back and forth across the road.

Some producers may live on the east side of the road, but pasture cattle on their land west of the highway, he said, using their address as a loophole around the testing requirement.

Four herds in Park County were quarantined after brucellosis was found in cattle last fall and about a month ago. State veterinarians have said the cattle likely were infected by elk, although serological testing continues.

Brucellosis is a bacterial disease that can cause pregnant cattle, bison and elk to abort their calves. It also can cause undulant fever in people who can be infected by drinking raw milk or through blood contact, such as during calving or hunters who field dress infected animals.

“That’s why pasteurization was invented, to deal with brucellosis,” Bischoff said.

Putting all of Park County in the designated surveillance area could help maintain Wyoming’s class free status, Bischoff said. Currently, the United States Department of Agriculture is allowing Wyoming to keep its status by testing herds within the DSA and removing cattle infected by brucellosis. But if a cow outside the DSA tests positive, the entire state could lose its status and every livestock producer would be forced to test cattle at sale, driving up the expense, he said.

State law allows reimbursement for brucellosis testing at $3.50 per head, Bischoff said. The expense is less of a hit at times like this, when beef prices are high. If the state is declassified, a producer could face losing an entire herd if one or a few cows test positive. The cattle would be sold to slaughter at market price, he said.

“The price, right now, is good,” Bischoff said, “but you don’t want to have to depopulate and buy back all those (new) cows” in addition to losing herd genetics.

A new report issued by Montana Department of Livestock officials said the designated surveillance area around Yellowstone Park saves cattle producers outside the zone between $5.5 million and $11.5 million annually in avoided costs for disease testing. The report says only 3 percent of Montana’s 1.4 million cattle are within the zone created last year to manage brucellosis.

Brucellosis is a puzzle that’s hard to solve, Bischoff said. It would help if every cow was vaccinated, although the best vaccine is effective against the disease only about 60 to 70 percent of the time. Some research indicates cattle need booster vaccinations, although that may not be any more. Even cows that abort may not test positive for the disease, although that’s a typical effect, he said.

He credits state officials with good brucellosis testing and enforcement, in cooperation with federal officials. The disease has been eliminated in every U.S. state except those areas bordering Yellowstone National Park, where wildlife remain infected.

Officials in the three states surrounding Yellowstone are attempting to control it — Montana officials are negotiating how to handle bison that leave the park; Wyoming wildlife officials are testing elk to determine the extent of brucellosis infection.

Bischoff recommends testing for most cattle of reproductive age, which he said can lead to higher profits for producers.

“I’d rather find it out early,” he said, to keep from entering calving season “with a bunch of open cows.”