Washington State Confirms First H5N1 Avian Flu Detection In Dairy Cattle

By Stephanie Soucheray

Late last week the US Department of Agriculture’s National Veterinary Services Laboratory confirmed the detection of H5N1 highly pathogenic avian influenza (HPAI) on two Yakima County dairy farms in Washington.

“This marks the first known case of HPAI in cattle in Washington state,” state officials said. Since March 2024 dairy cattle herds in 19 states have documented H5N1 infections, including neighboring Idaho.  

2 farms under quarantine 

“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,” officials said. “The two farms are under quarantine and have employed strict biosecurity measures. Veterinarians are working to treat sick cows.”