You are here

Ranchers Fear Ruin From Brucellosis


Cattle are moved across public lands near Pinedale, inside Wyoming’s Designated Surveillance Area for brucellosis. The area is a hotbed for the transmission of the disease from elk to cattle, and stockmen worry that a herd’s exposure to brucellosis could be costly, possibly ruinous. (Flickr Creative Commons/Theo Stein-USFWS)

WyoFile and National Parks Traveler have collaborated to produced a robust package of multimedia stories that examine the brucellosis issue in the Greater Yellowstone Ecosystem, its effect on bison and livestock management, and efforts to repopulate areas of the American West with bison. This is the final installment to the series, which can be found at National Parks Traveler and WyoFile — Ed.

By Angus M. Thuermer Jr.


This spring, a rancher in Sublette (Wyoming) County held his breath as his herd of cattle, which had been under quarantine for a year and a half, underwent blood testing for brucellosis.

In two previous tests, the cattle had come out clean. If that trend continued on the third test, the ranch would be allowed to resume normal operations.

When results in June showed no indications of exposure to the bacterium, Wyoming livestock was brucellosis-free for the second time in the last seven years. The only other such break was a four-month period in 2015.

Those who don’t know the difference between a dally and a doggie might not think much of a quarantine. The debate over the role of wild bison in spreading the disease to cattle often overshadows the implications of stock infections. But there can be dire economic consequences from a positive brucellosis test of domestic stock, and ranchers carry much of the corresponding burden.

In Sublette County, where elk are known to have spread brucellosis to cattle in several instances, the consternation is eternal, said Joel Bousman, a Boulder-area rancher. “We always worry,” he said, especially in the spring when cows that haven’t become pregnant are shipped off. A cow that doesn’t get pregnant may be a harbinger of trouble.

If brucellosis, known for causing cattle abortions, was the cause of the non-pregnancy, the bacterium would likely show up in a blood test as the animal moves from ranch to auction yard and beyond.

When brucellosis is detected, livestock authorities clamp down on the rancher. They restrict the movement and sale of cattle, depending on what a follow-up investigation reveals. (Brucellosis can only be confirmed in a necropsy — blood tests only indicate exposure to the bacterium.)

Today, the most common method for resolving infections is herd quarantine and “bleed out.” Veterinarians test the animals, slaughter those that reveal exposure to brucellosis, and test again until all results come back negative three times.

The cost of testing, to say nothing of being barred from market and some range, “that’s all on you,” said Albert Sommers, another Sublette County rancher, state representative, and member of the governor’s Brucellosis Coordinating Committee on which Bousman also sits.

With an average quarantine cost estimated by University of Wyoming researchers at $140,000 for a 400-cow herd, “it could break the operation, Bousman said. “That’s what we worry about in the spring of the year.”

Joel Bousman, left, along with Brad Boner, received awards for being outstanding alumni during Ag Appreciation Week at the University of Wyoming in 2014. (University of Wyoming)

96 reactors in 8 years

With herds of infected elk surrounding his ranch in Boulder, an outpost next to the Wind River Range just south of Pinedale, Bousman knows the threat is real. Ninety-six cattle in eight Wyoming herds tested positive for exposure to brucellosis between 2004 and 2012, according to a U.S. Department of Agriculture paper published in 2014. Altogether there were 3,348 cattle in the affected operations.

But Bousman, a Sublette County commissioner, doesn’t need a government paper to inform him. He has firsthand experience. His cattle were quarantined about a dozen years ago after being designated as a “contact herd.” A neighbor’s stock had tested positive for brucellosis. At the time the U.S. Department of Agriculture’s Animal Plant Health Inspection Service operated under a strategy that saw that infected herd “depopulated.”

“They killed them all,” Bousman said of his neighbor’s stock, and “they paid him market value.”

All told, about 10 herds, including Bousman’s, were quarantined and checked as a result of the neighbors infection, Wyoming veterinarian Dr. Jim Logan said. “We tested a lot of cattle that winter,” he said.

Since then, however, the federal agency has shifted course, choosing quarantine, test, and slaughter over more expensive depopulation. “Now their philosophy has changed,” Bousman said.

The shift came when Logan and state veterinarians from Idaho and Montana convinced federal regulators that cattle themselves were no longer the principal risk. “The only risk factor was the reservoir [of brucellosis] in the wildlife in the greater Yellowstone area,” Logan told WyoFile. “They finally realized that killing cattle to stop a disease in a different species wasn’t going to solve the problem.”

Quarantine grinds against a rancher’s margins. While Bousman couldn’t immediately tally the costs to his Eastfork Livestock ranch, others have crunched the numbers.

At the University of Wyoming’s College of Agriculture and Natural Resources, Carolyn Hageman and Dannele Peck wrote a summary of financial impact quarantine could have on a rancher. If 400 breeding cows, plus some additional stock, were quarantined for a year, it would cost about $140,000, mostly for hay (priced at historical average of $89 a ton.)

The expenses to the producer of a “detected” cow-calf operation could range from $40,000 to $320,000. “The upper estimate of $320,000 was used to represent a worst-case scenario (representing depopulation with compensation to the producer),” researchers wrote in a summary. “…[A]n intermediate estimate of $144,000 (for a 400-breeding-head herd) was used to represent a scenario where confirmed positive animals are removed (test-and-remove) and affected herds are quarantined until three whole-herd tests are negative,” Hageman and Peck wrote.

A dozen years ago, when Bousman saw his neighbor’s ranch depopulated, the owner eventually bought more cattle. But years of his selective breeding and record keeping went down the slaughterhouse drain. “There’s no possible way to replace that,” Bousman said of the information and genetics. 

But back then there was cash from the federal government. “Now, the fear is the quarantine could actually break you,” Bousman said. “You always wonder, ‘how can you stay in the livestock business?’”

In a sense, Bousman was lucky. His quarantine occurred in the fall, when the herd was off its summer of public-land grazing and back at the home ranch where hay had been grown and baled for winter.

“If you’re going into winter, to private ground, and you came under quarantine, you stand a chance,” Bousman said.

Were it quarantined in spring, Bousman’s fourth-generation operation would have needed an additional two season’s worth of hay. That should be a federal responsibility, he said. “They should step up to the plate.”

Logan wouldn’t argue. “Is it fair for the producer to come up with the funds for extra feed?” he asked. “Perhaps not, but that’s the requirement.”

Federal and state authorities, along with local operators who share the public range, are trying to be accommodating, Sommers said. Nevertheless, there’s keen and logical interest, plus regulations, that seek to limit the mingling of infected and healthy cattle.

Now, Logan said, authorities “allow herds on quarantine to be turned out on public land or mingled as long as the only thing that was turned out is test-negative and had already calved.”

Elk, elk, elk

There’s little mystery about where the threat of brucellosis comes from. “We’re considered fairly high risk [being] close to the Muddy [Creek] elk feedground,” Bousman said. Sublette County is within Wyoming’s Designated Surveillance Area for brucellosis — where the bacterium is most likely to spread from wildlife.

Ranchers in the DSA vaccinate cattle every three years and test them every three years, Bousman said. “To vaccinate and bleed is additional time,” he said. “All the neighbors have to come. It’s an intense amount of additional labor.”

Wyoming’s Designated Surveillance Area covers all or parts of six counties where state and federal regulators keep a keen eye out for brucellosis in cattle. (Wyoming Game and Fish Department)

While Bousman worries about quarantines and infections, he believes the disease itself should be less of an issue nationwide today. One reason is pasteurization of milk, a process that eliminates the potential for undulant fever — brucellosis in humans.

“I don’t know anybody that doesn’t drink pasteurized milk,” he said. “That part of it has decreased the risk significantly.”

Also, the federal government switched the required vaccine from the more effective Strain 19 to RB-51, Bousman said. The former produced “false positives” — results that would indicate exposure to brucellosis when there was none. But the latter is not the enduring vaccination it was advertised to be, he said. So, cattle need a booster on a regular basis.

“If it’s no longer a risk to human health, let us go back to Strain 19, and don’t worry about the false positives,” he said. “But that will never happen.”

Sommers agreed. “They had a good vaccine they let go away,” he said. “If we could go back to the old Strain 19, this would be a non-issue.”

Wyoming Game and Fish Department, meanwhile, has a solution to the brucellosis problem among elk, Bousman said. West of the Continental Divide, including Sublette County, the game agency supports elk on 22 winter feedgrounds. Critics say the practice promotes disease spread. Game and Fish seeks to reduce the problem by delaying feeding as appropriate, and by spreading hay out to minimize mingling, among other actions.

Although feedgrounds are being attacked by numerous critics, they are “kind of a double-edged sword,” Logan said. “It does keep those elk off cattle feed,” he said. Without them, “we would have elk all over cattle feedgrounds. We’d have an explosion of brucellosis.”

Game and Fish used to vaccinate feedground elk against brucellosis but stopped in 2014, Chief Game Warden Brian Nesvik said in an email. The main reason was that a bulleted form of the vaccine that was shot into animals’ rumps was no longer being manufactured. Data also showed the program to be statistically ineffective.

Game and Fish tested a different and more controversial method of reducing perceived infection. It was a test-and-slaughter experiment at the Muddy Creek elk feedground.

“We’ve learned we can control it in the elk,” Bousman said. “We went through a period of about 3 years running the elk through the chute and blood-testing elk and depopulating only the ones that were sero-positive.” Positive blood tests declined from higher than 30 percent “to 6 or 7 percent,” he said.

Game and Fish hasn’t applied test-and-slaughter to its feedgrounds. “That part of it is very frustrating to me as a producer,” Bousman said.

Test-and-slaughter would be high profile and controversial, pitting private profit against public wildlife. Even still the practice would not eradicate the disease across the Yellowstone ecosystem, a goal that could be unattainable given public support for wildlife.

Logan is confident that the state’s surveillance for brucellosis among stock results in early detection. Nevertheless, the problem will likely persist. “We expect to find sporadic cases of brucellosis among our cattle herds as long as there is a wildlife reservoir of the disease in our state,” he wrote in a 2016 report to the U.S. Animal Health Association brucellosis committee. That’s small reassurance for ranchers.

“We’re caught in the middle, through no fault of our own, just because we live where we live,” Bousman said.

Please Support Independent National Park Journalism

Use the links below to make your donation to National Parks Traveler via PayPal, or send your check to National Parks Traveler, P.O. Box 980452, Park City, Utah, 84098. The Traveler is a 501(c)(3) nonprofit media organization. For U.S. residents, 100 percent of your contributions may be eligible for a tax deduction in accordance with applicable law. 

Featured Article


It's all about "them cows".  When I lived in that region, I always found it appaling that non-native domesticated cattle take precedence over Bison that are much better adapted to the region ...and even taste better.  Also, the cattle are destructive to the west especially in these dry desert regions they place them in.  They are better off being raised in Mississippi to east texas into NC where there's at least moisture to consistently grow feed.  

I never will understand the short sighted nature of the human race.  These folks were always some of the worst when it came to being illogical and lacking common sense.  

Let's Remember it was the Introduction of Cattle to lands adjacent to our national parks which caused the introduction of Brucellosis:  Those damn cattle are the source of Brucellosis which spread into indigenous bison and elk.  Ranchers today blame native ungulate wildlife when Brucellosis shows up; in fact, they should reveal their own cattle introduction history of the first occurrence of Brucellosis.


On the Origin of Brucellosis in Bison of Yellowstone National Park: A Review

Mary Meagher and Margaret E. Meyer
Conservation Biology
Vol. 8, No. 3 (Sep., 1994), pp. 645-653
Published by: Wiley for Society for Conservation Biology
Stable URL:


Brucellosis caused by Brucella abortus occurs in the free-ranging bison (Bison bison) of Yellowstone and Wood Buffalo National Parks and in elk (Cervus elaphus) of the Greater Yellowstone Area. As a result of nationwide bovine brucellosis eradication programs, states and provinces proximate to the national parks are considered free of bovine brucellosis. Thus, increased attention has been focused on the wildlife within these areas as potential reservoirs for transmission to cattle. Because the national parks are mandated as natural areas, the question has been raised as to whether Brucella abortus is endogenous or exogenous to bison, particularly for Yellowstone National Park. We synthesized diverse lines of inquiry, including the evolutionary history of both bison and Brucella, wild animals as Brucella hosts, biochemical and genetic information, behavioral characteristics of host and organism, and area history to develop an evaluation of the question for the National Park Service. All lines of inquiry indicated that the organism was introduced to North America with cattle, and that the introduction into the Yellowstone bison probably was directly from cattle shortly before 1917. Fistulous withers of horses was a less likely possibility. Elk on winter feedgrounds south of Yellowstone National Park apparently acquired the disease directly from cattle. Bison presently using Grand Teton National Park probably acquired brucellosis from feedground elk.

Add comment


This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

National Parks Traveler's Essential Park Guide