EHD fells deer and elk in numbers of states

Hundreds dead; news media interest spotty-

Late in many summers Epizootic Hemorrhagic Disease (EHD) or “blue tongue” kills deer and elk across the country. Whitetailed deer are the most commonly affected.  This viral disease is carried by biting midges that emerge in late summer.

Right now there are reports are of an entire herd of more than a hundred dead elk in northeastern New Mexico. Perhaps there are more than an hundred dead deer, mostly whitetails in central Montana. There are dozens of whitetail dead in North Dakota.

Hard frosts kill the biting black midges that spread the virus. Humans cannot get this disease or get sick from the venison unless the animal got a secondary infection of some kind while in a weakened condition

Well fed deer and elk are less susceptible to the disease. Some think overcrowded ranges of these animals are more likely to have outbreaks, though this is controversial. Long periods before frost comes seems to increase the number that die of EHD during a given year.

About 7-8 years ago there was a huge dieoff of whitetails in northern Idaho. My brother-in-law, living in Kamiah, ID said folks had clear dead deer off the roads every morning for a while as they went to work.

2012 was a very bad year for EHD. Last year in Michigan there was an official count of 15,000 dead with estimates as high as 70.000. It is though it will take 3-5 years for the deer to rebound. Indiana, Illinois, Wisconsin, Pennsylvania and Nebraska were hit hard too.

It is believed the EHD kills far more deer than Chronic Wasting Disease, although the viral agent is not so frightening as the all but indestructible prion.

The disease just gets sporadic attention from the media and organizations, perhaps because EHD doesn’t fit anyone’s political agenda for wildlife very clearly.

Here is the story about the hundred dead New Mexico elk in the ABQ Journal. which might have been EHD.




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  1. rork Avatar

    “Long periods before frost comes” made me wonder if that intended long dry periods or long hot periods or some such.
    Our pretty serious EHD death near me (SE Michigan, 2012), coincided with the lowest water in lakes and wetlands I have ever seen in 40 years, and since I am a bog person, I notice the details. Water got hot too – killed the hex hatch on my river (still essentially gone), and killed some lake’s northern pike. It’s anecdote, though I heard of such a connection from other sources. Midges did seem abundant where lakes had exposed “bottom”, also anecdote. Where I recreate (lumpy Fort Wayne moraine topography) it is essentially impossible to be over a mile from a lake, and there are typically more than a dozen wetlands per square mile that come in 20 flavors. It was sad and ghastly, but alas, I think we now have more appropriate deer numbers, but I expect that it will be inappropriate again by next year. 1 year-old does typically have 1 fawn here, older ones have 2 (sometimes 3), and coyotes, cars, and human hunters is all we’ve got besides disease. The DNR didn’t bother to alter the number of antlerless deer tags available on public lands right by me, but did reduce the number on some other lands in southwestern MI (where it might have been even worse than what I saw). Deer are in great condition this year – it’s super green out there.
    Practice your archery.

  2. jdubya Avatar

    Is this what is killing the moose in Minnesota?

  3. Jeff - NC Bowhunter Avatar

    EHD was really tough last year in NC. The northwestern part of the state saw thousands of deer deaths as a result of blue tongue. Hopefully the outbreak will not be as bad this year


  4. Ralph Maughan Avatar
    Ralph Maughan

    Regarding the death of the elk in New Mexico. . . . While EHD can be death in a day or two, an email reminded me that no one has mentioned foul play on the New Mexico ranch. Maybe they should.

    1. Rancher Bob Avatar
      Rancher Bob

      Of course the mention of foul play has to be brought up no evidence just a slight mention. Now if Ralph had posted the first story Robert posted back on Aug 29 the story line would have already stated the elk were not shot, but then ranchers and foul play go together a lot here. Indeed.

  5. ramses09 Avatar

    I love coming to this site, because of all the knowledge there is. It’s interesting to read all about the different states & their issues. Anti-Wolf folks always assume that it’s the wolves. It is a generational hatred passed down & somewhere that HAS to be broken, or we will never have wolves in this country.
    Thanks for all the interesting info.

  6. CodyCoyote Avatar

    Bluetongue — a/k/a/ Catarrhal Fever —is a different viral disease with similar symptoms to EHD.

    Bluetongue s/was native to South Africa and migrated here via a Western Europe vector, thanks again to alien exotic species moved around the planet by stockmen. Event hough the disease is transmitted solely by biting insects, the blood of cattle and animals originating in South Africa eventually made it to Western America, one flying biting midge or ? at a time. The first confirmed case of Bluetongue outside Africa was in Cyprus in 1943, just yesterday as far as these epizootic things go.

    EHD vs. BLuetongue ? Same symptoms, different viruses and distinct diseases.There are two variants of EHD and 5 variants of EHD. A vaccine exists for BLuetongue, and is effective in livestock. Bluetongue is almost never fatal to domestic animals but does cause weight loss and physical health issues, and there is some research indicating it can cause calf birthing failures.

    I takes a very astute veterinarian or epidemiologist to tell the difference between EHD and Bluetongue. Most practitioners just call it ” hemorrhagic disease” and treat the symptoms, since the disease is not transmittable from animal to animal. Of course nobody is treating any of this in the wildlife.

    The pathogenic fever present in Whitetail deer and some Muley herds ( and Elk ? Moose ?? ) in the West is not Bluetongue.

    Those clustered dead elk in New Mexico really have me wondering….

    1. CodyCoyote Avatar

      Correction – meant to say 5 variants of Bluetongue above . Me no typist.

      Also, there are nearly 3 dozen distinct serotype blood classes of the BT disease. These viruses have had a long time to evolve their craft , but have only been present outside of South Africa or SW Asia for about 60 years max.

  7. rork Avatar

    Today Michigan DNR and others (allow me to joke) from an inferior university down the road, press released that 25-50 deer maybe dead of EHD near Muskegon, but there are probably more reports to come, as hunter get to scouting more. Appears to be the very localized, not too terrible kind of thing we are somewhat used to, not like last year. No other dead deer have tested positive this year.
    Too boring for news coverage so far I think. Ahha, I finally found where they put them:

    Oh, thanks Cody for those last tidbits. It made me go look a bit more.


Dr. Ralph Maughan is professor emeritus of political science at Idaho State University. He was a Western Watersheds Project Board Member off and on for many years, and was also its President for several years. For a long time he produced Ralph Maughan’s Wolf Report. He was a founder of the Greater Yellowstone Coalition. He and Jackie Johnson Maughan wrote three editions of “Hiking Idaho.” He also wrote “Beyond the Tetons” and “Backpacking Wyoming’s Teton and Washakie Wilderness.” He created and is the administrator of The Wildlife News.

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