Domestic cat dies after H5 bird flu infection in Washington

An outdoor domestic cat in Washington has died after testing positive for H5 avian influenza, officials said. It is the first confirmed case in the state linked to exposure from an infected wild bird.

The Washington State Department of Agriculture said on Tuesday that testing confirmed the presence of highly pathogenic avian influenza H5, commonly known as bird flu, in a cat that died in Grant County. Further subtyping is underway.

Based on current surveillance data, officials said the case is consistent with other H5 detections in wild and domestic birds across the state, and that exposure to a wild bird is considered the most likely source.

The Grant County Health District said it has been working with the pet’s owners, the agriculture department, and the Washington State Department of Health to provide guidance, testing, and preventive treatment to people who were in contact with the animal.

Officials said no human infections have been identified in connection with the case.

State wildlife officials have reported multiple recent detections of avian influenza in wild birds, including hawks, owls, and eagles, as well as in omnivorous mammals such as raccoons and skunks. Officials said these species, like outdoor cats, may scavenge infected birds, increasing the risk of transmission.

“Many migratory birds overwinter in fields, backyards and around water sources across Washington State,” said Dr. Amber Itle, the state veterinarian at the agriculture department. “As birds concentrate, so does the avian influenza virus, increasing the risk of environmental contamination and spillover into domestic poultry, wild predatory species, and even our beloved outdoor domestic cats.”

Since the start of the current U.S. avian influenza outbreak in 2022, 149 domestic cats nationwide have tested positive for bird flu. Four of those cases occurred in Washington and were linked to raw pet food. The Grant County case is the first confirmed domestic cat infection in the state associated with exposure to an infected wild bird.

The case comes as Washington continues to monitor avian influenza risks following a fatal human infection reported last year.

In November 2025, a resident of Grays Harbor County became the first person globally confirmed to be infected with, and later die from, the H5N5 strain of avian influenza after contact with a backyard flock exposed to wild birds.