(COLORADO) — Colorado Parks & Wildlife has identified several cases of Highly Pathogenic Avian Influenza (HPAI) in a black bear, mountain lion and skunk according to a press release sent Thursday afternoon on Feb. 9.
CPW says the black bear out of Huerfano County was affected by the disease in October. The skunk found in Weld County tested positive for the disease in November. A mountain lion that died in Gunnison County was recently confirmed to have the disease. Additional suspected cases have been detected in the state with pending test results.
All three 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, per CPW. Testing was conducted by Colorado State University in Fort Collins and the National Veterinary Services Laboratory in Ames, Iowa.
This strain of HPAI was first confirmed in wild geese in Northeast Colorado in March of 2022, according to CPW.
The Huerfano County black bear was euthanized on Oct. 8, 2022, by a CPW wildlife officer after they witnessed it having seizures. the bears 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, per the press release.
“The decision to humanely euthanize the animal by our wildlife officer was made following the abnormal behavior and knowledge that numerous infectious diseases cause neurological symptoms,” said CPW Area Wildlife Manager Mike Brown. “Extremely ill animals have difficulty moving and often act abnormally. While clinical signs of numerous diseases may be observed, diagnostic laboratory testing and necropsy services help determine the actual cause of death.”
The Gunnison County mountain lion was found dead just outside of city limits on Jan. 15, 2023, in an area where mountain lion activity is common, said CPW. The mountain lion had necrosis in the liver and bronchointerstitial pneumonia, which have been seen in domestic cats with HPAI, which warranted HPAI testing.
“It was only a matter of time before the first HPAI case was confirmed in Gunnison County based on known cases in adjacent counties,” said CPW Area Wildlife Manager Brandon Diamond. “While this is an interesting case study with the lion, it’s important to point out that HPAI has been documented previously in a variety of mammals from across the country. In Gunnison County, CPW routinely investigates reports of sick and injured wildlife and is always interested in hearing from the public if they encounter something that doesn’t look quite right.”
The numbers of HPAI cases in mammals are currently low. The majority of cases confirmed during this outbreak are in wild and domestic birds. The most commonly affected wild birds in Colorado have been geese, as well as raptors and other scavenging birds that eat goose carcasses, states CPW.
A number of wildlife species have been affected with the current strain of HPAI including skunks, foxes, black bears, bobcats, coyotes and raccoons among several others, per CPW. It has even been detected in marine mammals. CPW says 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.
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. 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.