On Dec. 18, 2024, officials from the Washington Department of Fish and Wildlife (WDFW) confirmed highly pathogenic avian influenza (HPAI) infections of the H5N1 virus subtype in two cougars in Clallam County and a raccoon from Walla Walla.

WDFW is working with the Washington Animal Disease Diagnostic Lab at Washington State University and the National Veterinarian Services Laboratories for HPAI testing. 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.