Two Washington state dairy herds have tested positive for highly pathogenic avian influenza (HPAI), according to a Feedstuffs report, adding fresh detections to the ongoing H5N1 outbreak in United States dairy cattle.

What was confirmed?

The report identifies the pathogen as HPAI and the affected sector as dairy cattle. No additional details on herd size, county location, clinical presentation, or diagnostic method appear in the source material. The number of affected animals, the index cow, and the route of suspected introduction are not specified in the Feedstuffs notice.

Why Washington matters in the outbreak

Washington sits at the western edge of an outbreak that has, over recent months, moved through dairy operations in multiple states. A confirmation in the Pacific Northwest extends the geographic footprint of the event beyond the initial cluster of affected states and raises immediate questions for veterinarians and producers in a region that previously reported no dairy detections.

What producers should expect at the herd level

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• Movement controls and testing requirements that match state and USDA Animal and Plant Health Inspection Service (APHIS) protocols for affected dairies.
• Bulk milk sampling and individual animal testing as the surveillance backbone for HPAI detection in lactating cattle.
• Biosecurity review of milk-hauler routes, hospital pen traffic, and shared equipment, which are recognized risk pathways on affected operations.
• Coordination with state veterinarians and the USDA National Veterinary Services Laboratories for confirmatory testing.

Public-health and regulatory implications

HPAI A(H5N1) in dairy cattle carries documented public-health considerations. Federal surveillance has previously identified conjunctivitis and mild respiratory illness in dairy workers exposed to infected cows, and the USDA Food Safety and Inspection Service continues to require H5N1 testing of retail dairy samples as part of its monitoring program. The Food and Drug Administration (FDA CVM) has likewise evaluated pasteurization and found the process inactivates the virus in commercially sold milk; raw milk consumption remains a separate risk pathway. Any new herd confirmation triggers state-level reporting and feeding into the federal tally maintained by APHIS.

What the source does not say

The Feedstuffs item does not name the laboratory that confirmed the detections, the HPAI subtype beyond "highly pathogenic avian influenza," the date of confirmation, or the official quoted in the announcement. Veterinary teams seeking the laboratory confirmation report, the case report, and any quarantine order should consult the Washington State Department of Agriculture and the USDA APIS HPAI in livestock dashboard, where case counts and state-by-state breakdowns are updated.

What to watch next

If the pattern in previously affected states holds, expect a state Department of Agriculture bulletin within days of the initial Feedstuffs notice, followed by APHIS updates to the national dairy herd case count. Practicing veterinarians in Washington and neighboring states should review client biosecurity plans now and confirm that bulk tank and individual cow testing pathways are in place before clinical signs appear, since pre-movement and surveillance sampling have driven most early detections elsewhere in the outbreak.