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Brucellosis panel updates cattle ranchers on disease testing

by Wyoming Livestock Roundup

Pinedale – While brucellosis is not fatal to cattle or humans, and symptoms usually go undetected, it is on the federal government’s “Most Wanted” list as a livestock disease that brings a lot of rules, research and anxiety.

            Eradicated in the rest of the country, the U.S. Department of Agriculture continues to monitor livestock around Grand Teton National Park and Yellowstone, where elk and wild bison carry the disease.

            Under certain conditions, it can transmit to cattle, and the USDA’s Animal and Plant Health Inspection Service (APHIS) sets rules for Wyoming, Montana and Idaho, which in turn have their own rules. The designated surveillance area (DSA) of western Wyoming includes Sublette, Lincoln and Sweetwater counties.

            All cattle to be shipped outside the DSA must first have blood drawn and tested by Wyoming Livestock Board (WLSB) regulations. Blood is sent to the Wyoming State Veterinary Lab (WSVL) to look for indicators of brucellosis. 

            The first test looks for a seropositive result. Herds with reactors are quarantined and movements restricted, with more testing until APHIS and state veterinarians get three clean whole herd tests.

Pinedale meeting

            On Jan. 25 in the Pinedale Library’s Lovatt Room, Pinedale rancher and Rep. Albert Sommers welcomed more than 100 ranchers and ag notables about recent developments in Sublette cattle herds being tested for brucellosis. 

            The meeting was designed to have each of seven panelists update the public and allow time for questions, answers and comments.

            Notables included Wyoming Department of Agriculture Director Doug Miyamoto, Wyoming Stock Grower’s Association Executive Vice President Jim Magagna, Joe Budd with Gov. Gordon’s office and other WSLB members.

            Mike Henn, manager of the co-sponsoring Sublette County Conservation District, said a lot of constructive dialogue took place with good ideas and solid information exchanged. The Green River Valley Cattlemen’s Association was another sponsor.

Sublette herds

            From Oct. 25 through Dec. 11, 2019, eight beef cattle herds in Sublette County were investigated due to non-negative brucellosis test results after blood tests done just before cattle were shipped showed a possible positive, according to State Veterinarian Jim Logan.

            Wyoming State Vet Lab tested blood from about 85,000 cattle and domestic bison from across the state last year. Initially, tests in all three states until June 2019 were done with the less sensitive rapid automated presumptive test, which Logan called “quick and efficient.” The test was discontinued due to software issues.

            APHIS, state veterinarians and lab biologists then switched to the more sensitive fluorescence polarization assay (FPA) test to find more cattle in suspect and reactor ranges, which are called non-negatives.

            With FPA screenings bringing more cattle under the microscope, everyone needed to verify which two-year-old heifers and cows were actually infected.

New protocol

            On Nov. 14, 2019, the state and APHIS agreed to further test FPA-positive animals, with 25 suspects in 16 herds. They then tested them with the more sensitive buffered acidified plate antigen (BAPA) test and then complement fixation (CF) test, according to Logan. The CF test has a sensitivity level of about 98 percent. Overall, the total number of non-negative results in Wyoming was just under .03 percent, Logan said.

            Last December, APHIS approved the new protocol that Wyoming was already using in Sublette County.

            This put Sublette ranchers into limbo of not being able to ship cattle and not knowing if their herds would be quarantined while awaiting results, they said. 

            “All but three of those herds we were able to release from movement restrictions within an average of two and a half weeks,” Logan said

            Initially, four herds had one “non-negative” animal, three herds had two each and one herd had more than two.

            “Three Sublette herds are still under quarantine and one herd could be cleared pending further serological results,” Logan said.

            The only way to prove, without a doubt, an animal was infected with brucellosis is to send the carcass to the Wyoming State Vet Lab for a necropsy. Six Sublette County cattle took that route.

            “Tissue cultures from one animal from Sublette County did grow field strain Brucella abortus,” he said. “Only about 40 percent of serological positive animals yield culture growth of the bacteria.”

            Herds under quarantine must have one final test after calving to be released.

`           “We certainly hope our quarantined herds can qualify for release in time for spring turnout,” Logan said.


            Other counties had non-negative results last year, including two investigations in Park County and two quarantined herds. An investigation in Lincoln County and one in Teton County were released.

            WLSB Director Steve True said his goal is to market for the state as a whole to have free and open markets.

            “Our goal in the designated surveillance area is to never have any cattle leave Wyoming with the brucellosis infection,” said WSVL’s Dr. Brant Schumaker.

            “Most cattle testing positive with the FPA test were negative under the BAPA test” he said. “However, that test takes twice as long to run than the FPA screening.”

            Hot heifers and cows in Sublette County were all bangs vaccinated and some believe that could put some brucella in their blood, but Logan called that unlikely.

            “False positives create a lot of concern for ranchers to market and move their cattle,” a rancher said. “If the test results could be returned more quickly, it would greatly help all the producers.”

            Producers should plan ahead for those blood tests well before cattle are shipped so they aren’t blindsided by a non-negative result, one Sublette rancher advised.

            WSVL Director Dr. Will LaGried said, especially in November, the lab performs more than 3,000 tests on any given day.

Game and Fish Department

            Should Wyoming Game and Fish Department (WGFD) go back to its “test and removal” of seropositive elk at Sublette County feedgrounds?

            Director Brian Nesvik said the policy is not effective long term, takes a lot of work and money, is limited in scope and brings negative publicity. He and Sommers suggested it might be useful in areas without feedgrounds.

            Through 2015, WGFD personnel tried to vaccinate 2,500 elk calves a year at all feedgrounds except Dell Creek Feedground near Bondurant, which is the “control” where no elk have ever been vaccinated. 

            Each winter, a percentage of elk cows are trapped in a log corral at the feedground where WGFD biologists draw blood. Biologist Brandon Scurlock said the prevalence there is 30 to 35 percent.

            In 2019, overall surveillance of 230 elk at seven feedgrounds showed 136 yearlings and adult cows tested seropositive for brucellosis, 40 percent average overall.

            Dell Creek Feedground is one of the most important to prevent elk from commingling with cattle, with two cow/calf operations within a mile or so, according to Biologist Brandon Scurlock.

            “Brucellosis in elk is fairly benign and non-fatal,” he added.

            One audience member asked Nesvik if WGFD would oversee a program to compensate ranchers for brucellosis costs, which the director said he would if the Wyoming Legislature offered the appropriation. 

            The wildlife agency does not receive any state funding.


            Several people said communications between ranchers and officials were poor last fall while ranchers awaited test results, leading to many rumors. Specific herds and owners are confidential under state law to prevent negative publicity and marketing problems.

            “We’re going to fill that vacuum with our own speculations,” Sommers said.

            Another attendee agreed, “It pits us against one another and we can’t have that.”

            Pinedale rancher Charles Price suggested planning ahead. 

            “We know we need to do our blood tests. Maybe do them a week or 10 days ahead? Then if there’s a problem, they can be isolated and avoid some of this,” said Price.

            Compensation for indemnity was another issue discussed. Not so many years ago, APHIS wanted an entire herd with positives slaughtered, with some compensation offered. The state has money set aside but with a lot of strings attached, Sommers said.

            It might be possible to set up sideboards to determine who might be compensated for false positives or condemned cattle, True said, adding they could come back to talk more about that.

            “We would never go back to removing the whole herd,” said Logan. “Now we can get positives out before it spreads.”

            Another rancher offered to experiment with vaccines, but Schumacher said local herds provide too small of sample sizes.

             Dr. Don Beckett of APHIS said, “It is the Department of Homeland Security banning use of live brucellosis bacteria. People in the agriculture sector could petition Congress to have that changed.”

            “Do we think now is the time for all of us combined to make a more united effort to try and address this issue?” asked rancher and Sublette County Commissioner Joel Bousman.

            Beckett advised those seeking that change, who include state veterinarians and research labs, to work with state and federal officials and legislators and add a voice to theirs.

            Joy Ufford is a corresponding writer for the Wyoming Livestock Roundup. Send comments on this article to

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