Avian influenza cases increase in Washington
Updated Dec. 18, 2024 to add the confirmation of a second cougar in Clallam County with HPAI.
Washington Department of Fish and Wildlife (WDFW) biologists and veterinarians are seeing an uptick in probable cases of highly pathogenic avian influenza (HPAI) in Washington wildlife, including mammals, and want to remind people of safety procedures regarding sick or dead wildlife they may encounter.
WDFW has confirmed HPAI in numerous wild birds this fall (and is awaiting confirmation on several other suspected cases), especially in Western Washington. In addition, WDFW has just confirmed HPAI infections of the H5N1 virus subtype in two cougars in Clallam County and a raccoon from Walla Walla.
WDFW works with the Washington Animal Disease Diagnostic Lab at Washington State University and the National Veterinarian Services Laboratories for HPAI testing.
While the spread of HPAI, in particular H5N1, from birds to mammals is concerning, it is not surprising. To date, there is no indication that HPAI viruses are circulating in wild mammals. Rather, cases are directly related to mammals scavenging on infected wild birds such as waterfowl. Since 2023, WDFW has confirmed cases of H5N1 in striped skunks and a bobcat in northeast Washington, harbor seals in Puget Sound, and raccoons in various areas, in addition to the recent raccoon and cougar cases. H5N1 has also been detected in red foxes, striped skunks, and bobcats in other North American states.
The U.S. Department of Agriculture maintains a web map detailing confirmed wild mammal HPAI cases in the United States. According to the Centers for Disease Control and Prevention (CDC), as HPAI viruses continue to evolve, other mammals may become infected, although the CDC maintains that the risk of HPAI H5N1 to humans is low.
Avian influenza viruses occur naturally among wild aquatic birds and can infect poultry and other animal species through saliva, nasal secretions, feces, and contaminated surfaces. Bird flu viruses are not easily transmissible from birds to people, but without proper hygiene, or if in prolonged contact with a sick bird, the risk increases. While it is unlikely that hunters or people feeding wild birds will contract HPAI viruses, take steps to ensure all equipment (boots, clothes, vehicles, firearms) are cleaned and disinfected to prevent spreading diseases from one area to another; wear disposable gloves when cleaning harvested birds or bird feeders; do not harvest or handle wild birds that are obviously sick or found dead; do not eat, drink, or smoke while cleaning game; and wash tools and work surfaces used to clean game birds with soap and water, then disinfect with a 10% solution.Both the CDC and Washington State Department of Health have additional prevention tips and information on what to do if you make contact with sick or dead wild birds.
Given what is currently known about H5N1, it is believed to be rare for the virus to infect domestic pets such as dogs, but cats are more vulnerable. Help protect pets by preventing them from scavenging or interacting with sick or dead wild animals, discontinue practices that cause birds to congregate such as feeding waterfowl, and avoid handling sick or dead birds or other wildlife. If you must move a dead animal, wear an N95 mask and gloves, double bag it, and place it deep into the garbage where scavenging animals can’t find it. You can also bury or incinerate carcasses.
More information on avian influenza in wild species is on WDFW’s avian influenza webpage. HPAI cases are posted there as they are confirmed. Please report sick or dead birds or other wildlife using WDFW’s online reporting tool to help monitor the spread of viruses and notify the public to take precautions.
WDFW works to preserve, protect and perpetuate fish, wildlife and ecosystems while providing sustainable fish and wildlife recreational and commercial opportunities.
