SALEM, Ore. -- Milk from a Morrow County dairy tested positive for highly pathogenic avian influenza, the first detection of HPAI in Oregon dairy cattle, the Oregon Department of Agriculture said Tuesday.

Preliminary detection of HPAI was identified through Oregon's routine statewide milk surveillance program, with preliminary results reported by the Oregon Veterinary Diagnostic Laboratory at Oregon State University last Friday.

ODA immediately initiated an on-farm investigation and submitted additional samples to the U.S. Department of Agriculture National Veterinary Services Laboratory for confirmation. Positive results were confirmed on Tuesday.

Oregon’s routine statewide milk surveillance program identified the detection, demonstrating the effectiveness of the state's ongoing monitoring efforts. No additional affected dairies have been identified at this time.

Pasteurized milk and dairy products remain safe to consume, and there is no concern about the safety of the commercial milk supply. Pasteurization effectively inactivates the HPAI virus, and milk from sick animals is prohibited from entering the commercial milk supply.

The U.S. Food and Drug Administration continues to advise against consuming raw (unpasteurized) milk because it does not undergo the heating process that kills viruses and bacteria.

"While this detection is significant, it is not unexpected given the continued spread of HPAI among dairy cattle nationally," said Dr. Ryan Scholz, State Veterinarian for ODA. "Oregon's milk surveillance program worked exactly as intended, identifying this infection quickly and allowing us to respond rapidly with our state and federal partners."

"This detection demonstrates the value of the monitoring and preparedness efforts supported by Oregon's dairy industry and animal health partners since 2024."

ODA has placed the affected dairy under quarantine, and enhanced biosecurity measures are in place. The quarantine restricts animal movement and implements additional disease control measures while response activities are conducted.

Response activities are focused on the impacted dairy and associated epidemiologic investigation. In most cases, infected dairy cows are expected to recover within a few weeks.

ODA is coordinating closely with USDA, Oregon Health Authority and Morrow County Public Health officials, OVDL, and Oregon's dairy industry partners as the investigation continues.

Oregon's statewide dairy surveillance program, launched in December 2024, was established to detect HPAI early and support rapid response efforts. The program allows state and federal officials to implement disease control measures quickly when detections occur.

Public health officials are providing education to farm workers exposed to infected animals and will monitor them for symptoms of avian influenza throughout the outbreak.

"With the use of appropriate personal protective equipment, the risk to farm workers remains low. Our public health approach is focused on ensuring rapid testing and treatment for any individuals who develop symptoms to prevent severe disease," said Melissa Sutton, M.D., medical director, respiratory viral pathogens, OHA.

No human cases associated with this incident have been identified in Oregon. According to OHA and the Centers for Disease Control and Prevention, the current public health risk to the general population remains low. No cases of person-to-person transmission associated with this virus have been identified.

HPAI was first detected in U.S. dairy cattle in March 2024 and has since been identified in multiple states. USDA provides current information on HPAI detections in livestock. Oregon began statewide dairy milk surveillance in December 2024 and continues to test milk from all licensed dairy operations routinely.

ODA appreciates the cooperation of Oregon dairy producers and industry partners who participate in ongoing surveillance, disease reporting, and biosecurity efforts that help protect animal health and Oregon's dairy industry.

Symptoms of HPAI in Dairy Cattle

Symptoms can include:

• Decrease in feed consumption with a simultaneous decrease in rumination and rumen motility.

• Respiratory signs, including clear nasal discharge.

• Acute drop in milk production.

• Abnormal tacky or loose feces.

• Lethargy.

• Dehydration.

• Fever.

• Thicker, more concentrated, colostrum-like milk, or no milk production in severely affected animals.

Some infected cattle may show no clinical signs. Most infected cattle recover within two to three weeks.

Suspected cases of HPAI in any animal species should be reported immediately to ODA at 503-986-4711.

For more information regarding HPAI in livestock, please visit the ODA HPAI webpage (http://oda.direct/AvianInfluenza).