#19,365
While the USDA's dashboard (above) has not yet been updated, late yesterday the State of Washington and the USDA/APHIS announced that two cattle herds in Washington have tested positive for HPAI H5 clade 2.3.4.4b (N type and genotype pending); the first such detection in that state.
This is the first new state to report an outbreak in 2026 (the last being Wisconsin in December 2025), and the 20th state to report dairy cattle H5N1 infection (Oregon is marked on the above map due to H5N1 in pigs).
First, the Washington State Announcement:
OLYMPIA – Oct. 8, 2026 –The USDA National Veterinary Services Laboratory (NVSL) confirmed the first detection of highly pathogenic avian influenza (HPAI) H5N1 in two Yakima County dairy farms in Washington state by the Washington Animal Disease Diagnostic Laboratory.For the last two years, the Washington State Department of Agriculture (WSDA) and the Washington Animal Disease Diagnostic Laboratory at Washington State University have conducted over 7,000 surveillance tests for HPAI that have all been free of the disease.This marks the first known case of HPAI in cattle in Washington state. Dairy cattle in a total of 19 states have been infected since the start of the outbreak in March 2024. Washington State Department of Agriculture conducted on-farm investigations, testing, and gathered additional epidemiological information to better understand this detection and limit further disease spread. The two farms are under quarantine and have employed strict biosecurity measures. Veterinarians are working to treat sick cows.Pasteurized milk products remain safe for consumers, and milk supply shortages are not expected.WSDA urges livestock owners statewide to report any clinical signs of illness to their veterinarian, including:
- Changes in milk appearance (thicker, often yellowish to brown)
- Decreased milk production
- Decline in feed intake
- Fever
- Respiratory symptoms
- Changes in manure
- Steep drop in rumination and rumen motility
If you notice any of these signs, isolate affected animals and contact your veterinarian and WSDA at 360-902-1878 or ahealth@agr.wa.gov.Most cattle affected by HPAI recover with supportive care with recovery typically taking about six weeks.“We appreciate how difficult this is for our dairy families, farmworkers and veterinarians that are working hard to keep animals safe and healthy,” said Washington State Veterinarian Amber Itle, VMD, MS. “The most important thing you can do is implement enhanced biosecurity and report symptoms immediately if animals show signs of illness.”HPAI can spread between dairy cattle through infected animals and contaminated milk, equipment, vehicles, clothing, footwear and other materials or people that move between farms. Wild birds can also carry HPAI, but they are not considered the primary source of spread of the virus between dairy herds.Protecting your herd
- Follow your biosecurity plan or write one with your veterinarian to incorporate enhanced biosecurity measures:
- Limit lactating animal movement between farms unless necessary
- Do not share equipment, vehicles or workers
- Clean and disinfect footwear before entering livestock areas
- Limit visitors and require clean clothing and footwear
- Isolate new animals for 30 days before introducing them to your herd
- Separate sick or suspect cattle from healthy cattle when possible
- Practice good milking hygiene and keep milk from sick or suspect cattle out of the bulk tank
- Restrict access to open water used by wild waterfowl
- Employ wildlife, wild bird, rodent and vector control
- Minimize contact with wild birds and other animals, particularly around cattle, feed, water and equipment
Dairy product safetyPasteurization inactivates viruses and bacteria in milk, including HPAI virus, helping ensure the safety of the dairy supply. Infected cows can shed the virus in their milk, making raw milk and other raw dairy products unsafe for consumption. Avoid raw dairy product consumption, and do not allow your pets to consume raw milk or other dairy products, or raw foods such as raw meat.Human health and safetyThe Centers for Disease Control and Prevention (CDC) and the Washington State Department of Health (DOH) currently consider the risk to the public from avian influenza to be low. However, people who work with or have recreational contact with infected birds, cattle or other potentially infected domestic or wild animals are at higher risk and should take precautions, including wearing personal protective equipment (PPE) such as gloves, masks, eye protection and fluid-resistant coveralls or other outerwear.
The USDA/APHIS statement:
USDA Confirms Highly Pathogenic Avian Influenza in Two Dairy Herds in Washington
Contact: aphispress@usda.gov
Milk Supply Safe; Considered Low Risk to Human Health and Safety
WASHINGTON, D.C., October 8, 2026—Today, the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) National Veterinary Services Laboratories (NVSL) confirmed via PCR (polymerase chain reaction) detection of highly pathogenic avian influenza (HPAI) H5 clade 2.3.4.4b in two dairy cattle herds in Washington. APHIS will complete genetic sequencing and announce final results as soon as they are available. The affected herds were tested after exhibiting clinical signs consistent with avian influenza. Prior to this detection, the herds consistently tested negative through routine surveillance conducted under the National Milk Testing Strategy program.
These are the first confirmed case detections of HPAI in livestock in the State of Washington. While dairy cattle in a total of 19 states have been infected since the start of the outbreak in March 2024, APHIS has seen cases in only a small number of states this year. APHIS is working closely with the Washington Department of Agriculture to conduct additional on-farm investigations, diagnostic testing, and epidemiological data collection to better understand the detection and prevent further disease spread.
The detection does not change USDA’s HPAI eradication strategy. Biosecurity is still key to mitigating the risk of disease introduction or spread between premises. APHIS recommends enhanced biosecurity measures for all dairy farms. Producers should immediately report any livestock with clinical signs, or any unusual sick or dead wildlife, to their state veterinarian. Financial assistance is available to enhance biosecurity and offset costs associated with HPAI.
This detection does not pose a risk to consumer health or affect the safety of the commercial milk supply. The U.S. Food and Drug Administration is confident that pasteurization is effective at inactivating HPAI virus, and that the commercial, pasteurized milk supply is safe. Dairies are required to send only milk from healthy animals into processing for human consumption; milk from impacted animals is being diverted from the commercial milk tank or destroyed so that it does not enter the human food supply.
According to the U.S. Centers for Disease Control and Prevention (CDC), HPAI viruses circulating in birds and U.S. dairy cattle pose a low risk to the general public in the United States. However, people who have job-related or recreational exposures to infected birds or mammals are at higher risk of infection and should take appropriate precautions outlined in CDC guidance.
While I'm confident in the ability of pasteurization to effectively kill the H5N1 virus in commercial milk, Washington is one of the few U.S. states that allows the sale of raw milk in grocery stores, natural food markets, food co-ops, and direct-to-consumer farm stores.
In 2024 and 2025 both Washington and Oregon repeatedly warned on the dangers of feeding raw milk or raw food products to cats, after a number of cats died from H5N1 (see Washington State (WSDA) Announces 2 Households with H5N1 Infected Cats Linked to Raw Food).
Hopefully people will take the risks seriously, and we won't see a replay of those events - or something worse - this fall.
