Washington Confirms Bird Flu in Dairy Cattle
The October 8 confirmation involved two farms in Yakima County, both of which have been quarantined and have employed strict biosecurity measures. Veterinarians are working to treat sick cows.
By R.E. Carlino | The Sequim Post
Washington has confirmed its first cases of H5N1 bird flu in dairy cattle, with infections detected at two farms in Yakima County, according to an October 8 announcement by the Washington State Department of Agriculture (WSDA).
The infections were confirmed by the U.S. Department of Agriculture's National Veterinary Services Laboratories following testing by Washington State University's animal disease diagnostic laboratory.
The discovery comes more than two and a half years after federal officials first identified H5N1 in U.S. dairy herds in Texas and Kansas in March 2024. The outbreak also raised human-health concerns when a Texas dairy worker tested positive in April 2024 after exposure to infected cattle.
Since then, dairy cattle infections have been reported in 19 states, including Washington. State agriculture officials say more than 7,000 surveillance tests conducted over the past two years had previously found no evidence of the virus in Washington dairy cattle.
Both Yakima County farms are now under quarantine and have implemented additional measures to prevent the virus from spreading. Veterinarians are treating affected animals while state officials investigate the infections. Although the confirmed cases are in Yakima County, WSDA is urging livestock owners throughout Washington, to watch for signs of illness and strengthen measures to protect their herds. Symptoms in dairy cattle can include reduced milk production, changes in milk appearance, decreased appetite, fever and respiratory problems. Farmers who notice these symptoms are advised to isolate affected animals and contact their veterinarian.
Washington State Veterinarian Dr. Amber Itle emphasized the importance of prevention and early reporting.
“The most important thing you can do is implement enhanced biosecurity and report symptoms immediately if animals show signs of illness,” Itle said in the WSDA announcement.
The virus can spread between dairy cattle through infected animals, contaminated milk and equipment, or through people and materials moving between farms. Wild birds can also carry H5N1, although they are not considered the primary source of transmission between dairy herds.
Dairy product safety
WSDA says commercially pasteurized milk remains safe to drink, and the agency does not anticipate milk supply shortages resulting from the confirmed infections.
Pasteurization inactivates the H5N1 virus in milk. However, infected cows can shed the virus in their milk, making unpasteurized products a potential health risk.
State officials advise consumers to avoid raw milk and raw dairy products. Pet owners are also advised not to give animals raw milk, other raw dairy products or raw meat because of the potential for infection.
Human health and safety
The Centers for Disease Control and Prevention (CDC) and Washington State Department of Health continue to consider the risk of H5N1 infection to the general public low.
People who work with dairy cattle, poultry or other potentially infected animals face greater exposure risks. Federal and state health officials recommend protective measures, including gloves, masks, eye protection and protective clothing when handling potentially infected animals.
According to the CDC's bird flu situation summary, 71 human cases of A(H5) bird flu have been reported in the United States since February 2024. Most were identified through monitoring of people with potential animal exposure.
The Washington announcement did not identify any infected dairy herds in other counties. WSDA continues to monitor the situation and advises livestock owners to report suspected infections promptly.
Farmers can contact the WSDA Animal Health Program at 360-902-1878 or ahealth@agr.wa.gov.
For additional information, see the WSDA October 8 announcement and the CDC Bird Flu Situation Summary.
⍟
