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Blood Test Required for All Stock Entering Yellowstone

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Date: August 18, 2008
Contact: Al Nash, 307-344-2015
Contact: Stacy Vallie, 307-344-2015

National Park Service

U.S. Department of the Interior


Yellowstone National Park

P.O. Box 168

Yellowstone National Park, WY 82190



August 18, 2008              08-072

Al Nash or Stacy Vallie (307) 344-2015






Blood Test Required Before Bringing Stock

Into Yellowstone National Park


Owners of horses, mules, and burros need to have proof that their animals have recently been tested for Equine Infectious Anemia (EIA) before bringing them into Yellowstone National Park.


The virus is spread from infected to healthy animals through large biting insects like horseflies. There is no vaccine, treatment, or cure.  The disease can be fatal to members of the horse family.


The only way to know if an animal is infected with EIA is to conduct a Coggins Test.  This test checks for EIA antibodies in the animal’s blood.  Proof that a negative Coggins Test has been conducted in the past 12 months must accompany every equine that enters the park.


Yellowstone National Park does not require a Certificate of Veterinary Inspection or perform brand inspections on stock animals.


Overnight stock use in Yellowstone’s backcountry is allowed at designated campsites beginning July 1; however some campsites and trails may open later than July 1 due to wet conditions.  Some trails may open for day use prior to that date depending on trail conditions.  There are no stock boarding facilities at park campgrounds or trailheads.


More information on stock use in the park is available by contacting the Backcountry Office at (307) 344-2160.




Did You Know?

Bison in Yellowstone.

There are more people hurt by bison than by bears each year in Yellowstone. Park regulations state that visitors must stay at least 25 yards away from bison or elk and 100 yards away from bears.