Bird flu hits Oregon dairy cattle for the first time as Washington’s infected herds climb into the dozens

Avian influenza has been confirmed in an Oregon dairy herd for the first time, federal officials said Tuesday, making Oregon the 22nd state with infected cattle weeks after an outbreak in neighboring Washington was linked to 3 human infections, including 1 death.^1,2

The herd was identified through Oregon’s ongoing surveillance for the virus in dairy cattle and had consistently tested negative before the detection, the US Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) said in a news release. The agency did not say where in Oregon the herd is located or whether it is connected to other infected herds.¹ As recently as November 2, Oregon agriculture officials said they had no confirmed or suspected cases in dairy cattle, and the state was listed as unaffected under the federal milk testing program.³

Washington confirmed its first infected dairy herds on October 8.⁴ The Washington State Department of Agriculture has since confirmed the virus in a Benton County herd that was found through routine surveillance before cows became ill, and Yakima County officials have reported 33 infected herds, according to the Associated Press (AP).^2,5

Three people in Washington have been infected after exposure at dairies with infected cattle. One, a Yakima County resident with underlying health conditions, died November 1 after being hospitalized, the first US avian influenza death in a year. A CDC spokesperson told the AP that the agency found no changes in that patient’s virus that would make it spread more easily or cause more severe illness.²

Third new state with a HPAI detection since October

Oregon is the third state since early October to report its first infected dairy herd, after Washington and Indiana.^4,6 Indiana’s case, confirmed November 2, was found through routine milk testing.⁶ The dairy cattle outbreak began in March 2024, and APHIS said it has seen cases in previously unaffected states this year.¹

Federal laboratory testing identified HPAI H5 clade 2.3.4.4b in the Oregon herd, and APHIS said it will announce genetic sequencing results when they are available.¹ Sequencing of the first Washington herds, which were tested after cattle showed clinical signs, found H5N1 genotype B3.13, the strain behind most US dairy herd cases. APHIS said those detections were consistent with transmission from Idaho, likely through cattle movement.^4,7

APHIS said it is working with the Oregon Department of Agriculture on additional on-farm investigations, diagnostic testing, and epidemiological data collection.¹

APHIS said the detection does not change USDA’s HPAI eradication strategy. The agency recommends enhanced biosecurity on all dairy farms and urged producers to report livestock with clinical signs, or unusual sick or dead wildlife, to their state veterinarian.¹

“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,” APHIS said in an announcement.¹

The CDC considers the risk to the general public low, but people with job-related or recreational exposure to infected birds or mammals are at higher risk.¹ CDC worker-safety guidance lists veterinarians and veterinary staff among those who may be exposed and recommends high-exposure personal protective equipment for tasks such as contact with potentially infected animals or their raw milk.⁸

References

1. USDA confirms highly pathogenic avian influenza in a dairy herd in Oregon. News release. USDA Animal and Plant Health Inspection Service. November 10, 2026. Accessed November 12, 2026. [email]
2. Washington state resident dies from bird flu following exposure to infected cattle. Associated Press. November 2, 2026. Accessed November 12, 2026. https://www.ajc.com/news/2026/11/washington-state-resident-dies-from-bird-flu-following-exposure-to-infected-cattle/
3. HPAI update. Oregon Department of Agriculture. November 2, 2026. Accessed November 12, 2026. https://www.oregon.gov/oda/Documents/Publications/AnimalHealth/AnimalDiseases/AvianInfluenza/SituationUpdates/2026.11.02_OR%20HPAI%20Update.pdf
4. Louis J. Avian influenza confirmed in dairy cattle in Washington for the first time. dvm360. October 9, 2026. Accessed November 12, 2026. https://www.dvm360.com/view/avian-influenza-confirmed-in-dairy-cattle-in-washington-for-the-first-time
5. WSDA confirms HPAI in dairy herd in Benton County. News release. Washington State Department of Agriculture. October 26, 2026. Accessed November 12, 2026. https://content.govdelivery.com/accounts/WAAGR/bulletins/4306fd8
6. McCafferty C. Avian influenza confirmed in Indiana dairy cattle. dvm360. November 6, 2026. Accessed November 12, 2026. https://www.dvm360.com/view/avian-influenza-confirmed-in-indiana-dairy-cattle
7. Update: genetic sequencing results for Washington dairy herd detection of highly pathogenic avian influenza. News release. USDA Animal and Plant Health Inspection Service. November 4, 2026. Accessed November 12, 2026. https://www.aphis.usda.gov/print/pdf/node/8350
8. Reducing exposure for workers to avian influenza A viruses. Centers for Disease Control and Prevention. May 6, 2025. Accessed November 12, 2026. https://www.cdc.gov/bird-flu/worker-safety/index.html