Background
Highly pathogenic avian influenza (HPAI) H5N1 virus has been detected in dairy cattle in multiple states. At this time, HPAI has not been detected in Oregon dairy cattle.
The HPAI virus (H5N1) detected in cattle in other states is in the same group (or clade) of avian influenza viruses that has been circulating in wild waterfowl throughout the US. While cases among humans in direct contact with infected animals are possible, the risk to the public remains low.
For information about HPAI detections in dairy cattle throughout the United States, visit the USDA's HPAI Confirmed Cases in Livestock webpage.
For information about HPAI detections in humans throughout the United States, see the Centers for Disease Control and Prevention (CDC) webpage: H5 Bird Flu: Current Situation.
Clinical Signs
The primary symptoms reported in clinically affected dairy cattle 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 at all in severely affected animals
Some infected cattle may be asymptomatic (subclinical). Most infected cattle can recover in 2-3 weeks.
Prevention
Cattle Import Requirements
In April 2024, the Oregon Department of Agriculture (ODA) enacted emergency import requirements for cattle being imported into the State of Oregon from any state with cattle currently affected by HPAI. In addition to existing import requirements, these emergency import requirements include:
- No cattle exposed to, infected with, or suspected to be carrying HPAI may be imported into Oregon.
- Non-lactating dairy cattle require:
- A Certificate of Veterinary Inspection (CVI) completed no more than 7 days prior to importation into Oregon; and
- A valid Import Permit issued by ODA.
- Lactating dairy cattle require:
- A Certificate of Veterinary Inspection (CVI) completed no more than 7 days prior to importation into Oregon; and
- A valid Import Permit issued by ODA; and
- A negative individual or laboratory-pooled PCR test for influenza A, conducted on milk samples collected no more than 7 days prior to importation into Oregon.
The full rule is available online through the Oregon Secretary of State's website.
Oregon Milk Testing
In December 2024, the Oregon Department of Agriculture (ODA), with significant input from Oregon's dairy industry and processors, launched its milk testing and monitoring program. The program aims to protect farms, farmworkers, and communities from H5N1 avian influenza. By January 2025 more than 75 percent of Oregon's milk was under surveillance. To date, Oregon has not detected H5N1 in dairy cattle or milk.
Food Safety
At this time, there is no concern about the safety of pasteurized milk or the meat supply . Since raw (unpasteurized) milk can be a vehicle for the transmission of human pathogens, the US Department of Agriculture (USDA) and US Food and Drug Administration (FDA) along with other dairy partners recommend that raw milk should not be consumed. Pasteurization of raw milk has been shown to kill harmful microorganisms, including HPAI viruses. Only milk from healthy animals is authorized for interstate commerce for human consumption and all dairy cattle are also subject to the Federal Meat Inspection Act and must be slaughtered and processed under inspection by USDA's Food Safety and Inspection Service, ensuring that all meat entering the food supply has been inspected and approved for human consumption.
If your cattle are showing signs of HPAI, notify to Oregon State Veterinarian immediately!
Oregon State Veterinarian
AnimalHealth@oda.oregon.gov
Phone: 503-986-4711
Resources
ODA Resources
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Bovine HPAI Sampler Training Video -
English,
Español
This video shows the methods of milk sampling, handling, and shipping for testing for Bovine HPAI -
Bovine HPAI Sample Kit Request -
English,
Español
Form to order sample collection kits for certified bovine HPAI samplers.
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Dairy Cattle Testing Instructions -
English,
Español
Instructions for collecting samples from dairy cattle for HPAI testing prior to exhibition -
Oregon Bovine HPAI Milk Sampler Application -
English,
Español
Complete this application to become approved to collect bovine milk samples for HPAI testing in Oregon. Approval is specific to an individual person and premises. If animals will be sampled on multiple premises, an application must be completed for each premises.
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Sign up to receive Animal Health Updates
Subscribe to receive species-specific animal health updates and announcements from the Oregon Department of Agriculture.
Other Resources
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CDC - H5 Bird Flu: Current Situation
Includes Information from the US Centers for Disease Control and Prevention (CDC) and links to resources about: current situation with H5N1 detections in USA; what CDC is doing; and protections for people. -
NMPF - Bovine H5N1 Information
Includes information from the National Milk Producers Federation (NMPF) and links to resources about: states with dairy cattle importation requirements or restrictions; states with confirmed HPAI cases; milk and meat safety; protecting the dairy workforce; signs in dairy cows; protecting dairy cattle; biosecurity resources; and National Dairy Farmers Assuring Responsible Management (FARM) Program expectations -
Secure Milk Supply
The Secure Milk Supply resources, while built around Foot and Mouth Disease (FMD), provide valuable resources for milk producers, veterinarians, processors, and regulatory officials for disease outbreak preparedness including customizable templates for developing biosecurity plans, disease monitoring, movement guidance, signs and posters and more -
USDA APHIS - HPAI Cases in Animals
Includes information and links to resources from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) about: frequently asked questions and recommendations; confirmed cases of HPAI in domestic livestock; latest USDA news; information for producers and veterinarians; biosecurity resources; Centers for Disease Control and Prevention (CDC) resources; and Food and Drug Administration (FDA) resources -
EPA - Disinfectants
US Environmental Protection Agency's (EPA) registered antimicrobial products with label claims that are effective against avian influenza virus -
FDA - Avian Influenza information
Includes information from the US Food and Drug Administration (FDA) about the investigation of avian influenza A (H5N1) virus in dairy cattle, status of the milk supply, and other FDA communications and resources