Saturday, February 11, 2023

Highly Pathogenic Avian Influenza linked to deaths of black bear and mountain lion in Colorado

Colorado Parks and Wildlife has identified several cases of highly pathogenic avian influenza (HPAI) in free-ranging wildlife. A black bear from Huerfano County was affected by the disease in October, a skunk from Weld County was found to be positive for the disease in November, and a mountain lion that died in Gunnison County was recently confirmed to have the disease. Testing was conducted by Colorado State University in Fort Collins and the National Veterinary Services Laboratory in Ames, Iowa.

HPAI has already killed thousands of wild birds in the U.S., including in Colorado. This strain of HPAI was first confirmed in wild geese in Northeast Colorado in March of 2022.

All three of the confirmed cases showed signs of HPAI before or after death including neurologic symptoms such as seizures or circling, general signs of illness such as weakness or lack of responsiveness to human presence, and organ damage including encephalitis, hepatitis, and pneumonia. Other similar suspected mammalian cases have been detected in the state, with confirmatory testing pending.

The Huerfano County black bear was euthanized Oct. 8, 2022, by a CPW wildlife officer after he saw it having seizures. Its remains were frozen until it could be transported to the health lab for testing. A necropsy revealed the bear had signs of HPAI, prompting CPW to test for HPAI. Later in October, a black bear in Alaska tested positive for HPAI.

The Gunnison County mountain lion was found dead just outside of Gunnison city limits on Jan. 15, 2023, in an area where mountain lion activity is commonplace. The mountain lion had necrosis in the liver and bronchointerstitial pneumonia, which have been seen in domestic cats with HPAI, so this also warranted HPAI testing.

A number of mammalian wildlife species have been affected with the current strain of HPAI in the U.S. including skunks, foxes, black bears, bobcats, coyotes and raccoons among several others. It has even been detected in marine mammals. These mammals likely become infected by feeding on wild birds that are sick or have died of HPAI; however, not every mammal that consumes a sick bird will develop HPAI. These recent Colorado cases add to a growing list of affected wildlife species.

Despite the variety of mammalian species susceptible to HPAI, the numbers of mammal cases are currently low. The majority of cases confirmed during this HPAI outbreak are in wild and domestic birds. The most commonly affected wild birds in Colorado have been geese, as well as the raptors and other scavenging birds that eat goose carcasses.

CPW continues to stress the importance of keeping your distance from wildlife, and specifically not handling sick or dead birds. Although rare, some HPAI strains can infect people. Links to recommendations for hunters and risks to pets are included below. The main protection for the general public is to avoid handling sick or dead birds and keep your distance from wildlife. See the CDC website for more information on protective actions for people.



Jeff
RockyMountainHikingTrails.com
HikinginGlacier.com
TetonHikingTrails.com

Ramble On (2nd edition book on the rich history of hiking)
Exploring Glacier National Park
Exploring Grand Teton National Park

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