Livestock disease found in eastern Idaho cow

The infected animal had been vaccinated.

This has been a perennial issue in areas surrounding the elk feedlots in Wyoming. It now seems that brucellosis has once again infected cattle in Idaho but it is too early to say where the disease originated. If brucellosis is found in another cattle herd in Idaho within a year then Idaho, once again, will lose its brucellosis free status and all cattle that are exported will have to be tested for the disease.

For years this scenario was held over the heads of people who support free roaming bison in Montana yet, when it came to pass, it turned out to be more of a minor inconvenience rather than the catastrophe the livestock industry claimed it would be.

This issue has been used rather effectively against wildlife for years but the disease is much less of a threat to human health than it was before the pasteurization of milk became the standard. The only way to contract brucellosis is by coming into direct contact with infected fetal tissue or by drinking unpasteurized milk. You cannot become infected by eating cooked beef.

Livestock disease found in eastern Idaho cow



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  1. Layton Avatar

    Is this the same thing that was called Undulent (sp?) fever when I was a kid?? I know that’s a long time ago, but the symptoms you describe here sound like the same thing.

  2. Layton Avatar

    Never mind — I did a search and found it. However they do say that you can contact it from sources other than milk.

    Undulant fever: An infectious disease due to the bacteria Brucella that characteristically causes rising and falling fevers, sweats, malaise, weakness, anorexia, headache, myalgia (muscle pain) and back pain.

    The disease is called undulant fever because the fever is typically undulant, rising and falling like a wave. It is also called brucellosis after its bacterial cause.

    The disease is transmitted through contaminated and untreated milk and milk products and by direct contact with infected animals (cattle, sheep, goats, pigs, camels, buffaloes, wild ruminants and, very recently, seals), and animal carcasses. Transmission can be through abrasions of the skin from handling infected animals. In the US, infection occurs more frequently by ingesting contaminated milk and dairy products. Groups at elevated risk include abattoir (slaughterhouse) workers, meat inspectors, animal handlers, veterinarians, and laboratory workers.

  3. Robert Hoskins Avatar
    Robert Hoskins

    What little information there is so far, the cattle herd is on a ranch near Rigby, between Idaho Falls and Rexburg. It is a “newly assembled” herd, which can mean a lot of things, but it mainly means that these cows came from a lot of different places, which raises the possibility that brucellosis came into the herd from a cattle source. This fact is something to pay close attention to; if it is a cattle source, then a lot of the thinking about the brucellosis threat in the elk and bison of the GYE will have to change. There is still no solid evidence for a wildlife source in Montana’s two brucellosis incidents in cattle. Although elk are being blamed, Montana still has to publish a final epidemiological report on those two incidents.

    On the other hand, Rigby is in the endemic area for brucellosis in the elk of eastern Idaho.

    Here is a URL for a recently published paper on brucellosis in elk in eastern Idaho:


  4. Ralph Maughan Avatar

    Thanks Robert,

    Rigby is well out on the cultivated portion of the Snake River Plain. It seems very doubtful the cattle there would come in contact with elk.

  5. Robert Hoskins Avatar
    Robert Hoskins

    Yes, I’ve been through Rigby several times on my way up to West Yellowstone. Heavily agricultural and not likely to attract elk. But since this is an “assembled” herd, what we don’t know is where all these cows came from and what their epidemiological history is. I get the impression that these cows haven’t been in Rigby for very long; probably assembled this fall off summer ranges or from livestock markets.

    Epidemiologically, this is going to be very difficult to track down. I worry that elk will get the blame after an incomplete survey. That’s what happened, I believe, in Montana.


  6. Jeff Avatar

    Elk do winter quite a ways out on the ag land of Eastern Idaho. I’d be curious to know where the cows in this herd were on summer pasture.

  7. Salle Avatar

    There sure aren’t any wild bison in the area so it can’t be blamed on them.

    It might be wise to recognize that no disease is ever completely eradicated, especially virus-type diseases. (Recently even polio has been making a comeback.) By that I mean that even in states where no brucella has been “detected” I’m willing to bet that there has been some presence even without absolute evidence ~ as in aborted fetus events ~ of infection.

  8. Nathan Hobbs Avatar
    Nathan Hobbs

    There is a domestic herd of elk a few miles south of Rexburg, and would not be surprised if there are a few others. The river also provides a bit of a channel for them, I have seen Moose at the Snake River bridge on the way to Rexburg and plenty of dead ungulates mostly deer but one or two that may have bee n elk on the side of the road on the stretch from Rexburg to Rigby.

  9. Ralph Maughan Avatar

    Thanks Nathan,

    If the farm is near the Snake River, there are deer and the occasional moose. The river does have substantial riparian zone. I’ve never seen elk, but they could follow river down.
    I wonder if the farm is near the Snake River or just out in the middle of the flats?

    In any case, the elk would have to mingle with the cattle and the elk would have to be infected. It is about 30 miles NW from Swan Valley where the last brucellosis outbreak in Idaho took place.

    Because this is a new herd, with cattle from a number of sources, I think the importation of an infected cow is the more likely explanation.

    The last time Idaho lost its brucellosis free status, it was hardly considered newsworthy by the Idaho media. They reacted much differently than the Montana or Wyoming media. I see this is an Associated Press article, with input from a reporter who knows Montana.

    Since then, the federal government has proposed splitting Greater Yellowstone area cattle into a separate category so that if brucellosis does show up the entire state does lose its class A brucellosis status. This is from the article, “Because the disease has been eliminated nationwide except for Yellowstone National Park and surrounding counties in Idaho, Montana and Wyoming, the government has proposed turning that area into a brucellosis ‘hot zone.’ “

  10. izabelam Avatar

    I hope they are not going to blame it on buffalo. There were 2 incidents where Idaho Wilflife Services shot single bulls in Island Park. And the broder of yellostone park is just over themountain from Island park which is not that far from Rigby and Rexburg.

  11. izabelam Avatar

    I meant to say border of Yellowstone

  12. Salle Avatar


    I live in the area and am aware of that. Bulls do not transfer the virus so there was no really good justification for shooting them. I don’t really expect that bison will be blamed but I do suspect that there are “carriers” among the general population of cattle around the west, even when no overt evidence of the virus is present. Cattle live in their own feces and other body fluids because they are usually penned up for a god portion of their existence.

  13. Ryan Avatar

    “There is a domestic herd of elk a few miles south of Rexburg”

    Look no further, elk farms are a great source of TB. There was a case of it a few years back here in Oregon. Elk farms are bad news.


    You be suprised how far elk travel into farm land, I saw a herd of elk outsite on Endicott WA, about 100 miles from the nearest tree in the dryland wheat farming area of Washington.

  14. Robert Hoskins Avatar
    Robert Hoskins

    At this stage, my own considered view is that the livestock agencies are going to have to prove brucellosis was NOT imported into this “newly assembled” herd. My fear however is that all the incentives, as we’ve seen in Montana and Wyoming over the years, are to blame wildlife without good evidence for doing so.

    I’ve written a few reporters and pointed out that the following are important things to know:

    1. the breed of cow found positive for brucellosis,

    2. where it came from originally,

    3. what summer range it was on this past year,

    4. whether it’s a heifer.

    5. same questions if other cattle are found positive.

    6. lastly, what exactly keyed officials onto this cow in the first place?


  15. dewey Avatar

    My former State Editor at the Casper Star Tribune in Wyoming, Ms. Nadia White, got a science journalism fellowship and spent an entire year studying and reporting the brucellosis issue in and around Yellowstone, and –ta da!–Kazakhstan, where undulant fever and the livestock disease are dealt with daily. K-stan has an excellent world class research program going on same, plus some grass roots cultural knowledge from a nation made up of folks advanced alongside old school nomadic herders.

    It may behooove Ralph or anyone else interested in this issue- that -won’t -go -away to contact Nadia. She’s a Journalism professor at UM in Missoula these days. Her collective reporting on the ins and outs of brucellosis are extensive.

    Google for “brucellosis, Nadia White” and you’ll see tons of links to get informed from.
    – – – – – –
    Thanks, Dewey Ralph Maughan

  16. Ken Cole Avatar

    Salle, brucellosis is a bacterial disease, not a virus.

  17. SAP Avatar

    From the article:
    . . . “the disease has been eliminated nationwide except for Yellowstone National Park and surrounding counties in Idaho, Montana and Wyoming . . .”

    From The Journal of of Veterinary Diagnostic Investigations, 2007:

    “Eighty feral swine were trapped from a herd that had been documented to be seropositive for Brucella and which had been used for Brucella abortus RB51 vaccine trials on a 7,100-hectare tract of land in South Carolina. The animals were euthanized and complete necropsies were performed. Samples were taken for histopathology, Brucella culture, and Brucella serology. Brucella was cultured from 62 (77.5%) animals. Brucella suis was isolated from 55 animals (68.8%), and all isolates were biovar 1. Brucella abortus was isolated from 28 animals (35.0%), and isolates included field strain biovar 1 (21 animals; 26.3%), vaccine strain Brucella abortus S19 (8 animals, 10.0%), and vaccine strain Brucella abortus RB51 (6 animals, 7.5%).”


    So, one sample of wild hogs in the south had a 77.5% infection rate. If we want to ignore B. suis and just look at B. abortus, these pigs were running 35% infected. The study was conducted in 2002-03. I doubt very much that they’ve rid South Carolina of feral swine in the intervening six years, to say nothing of the rest of feral swine country from Pennsylvania to central Texas.

    So much for the GYE being the last Brucellosis reservoir in the nation.

  18. Joseph Avatar

    I know some of the ranchers in Rigby run cattle in the nearby Big Hole Range, would be surprised if some of the cattle did not come from this area which is only seperated from the old Rainey Creek feed ground by Pine Creek Pass. Parts of last autumn’s prescribed burn in the Big Holes were heavily grazed by cattle, I thought there was a 2 year rest after a burn. There can be surprising numbers of elk along the lower S. Fork of the Snake, especially above Heise.

  19. Ralph Maughan Avatar


    Thanks for the information. If any of this recently-built herd did graze in the Big Holes, then certainly a possibility of elk transmission is there.

    I guess it might be some time before the origin of all the cattle is traced and an infection source determined, or at least narrowed down.

  20. Glenn Hockett Avatar

    Someone needs to look into the cows that were sent to slaughter – why were they sent to slaughter, were they tested and where did they come from? It is common for cattlemen to send “open” cows or cows that may have aborted a fetus to slaughter.


Ken Cole is a 5th generation Idahoan, an avid fly fisherman, wildlife enthusiast, and photographer. He is the interim Idaho Director for Western Watersheds Project.

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