Avian influenza A (H5N1) was first detected in dairy cattle in the U.S. in March 2024. On December 6, 2024, the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA-APHIS) announced the start of a National Milk Testing Strategy (NMTS) to conduct disease surveillance and prevent the spread of the virus to unaffected dairy herds and poultry flocks.
Minnesota joined the NMTS in early 2025. The state’s testing strategy used routinely collected bulk milk tank samples to test nearly all of Minnesota’s roughly 1,600 cow dairies for H5N1 on a monthly basis. This testing plan continued until four consecutive months of sampling and testing detected no H5N1 in Minnesota cow dairies. On August 22, 2025, Minnesota was able to move to Unaffected status and reduce testing frequency. However, federal restrictions on animal movement between states remain in effect. In February of 2026, testing moved from individual farms to silo sampling at Minnesota plants that receive Grade A cow milk. MDA dairy inspection staff in coordination with plant personnel are collecting samples and reviewing plant records. Samples are sent to the National Veterinary Services Laboratory (NVSL) in Ames, IA for analysis.
Cases of H5N1 in dairy cattle continue to be reported across the U.S. Dairy farmers should monitor their herds and contact a veterinarian immediately if cows appear sick. The Minnesota Board of Animal Health will report any new Minnesota detections and updates on cow cases in the state on its website. For the latest on national H5N1 detection in dairy cattle, visit the USDA website.
Farm Biosecurity
Biosecurity remains the strongest measure to prevent the spread of H5N1 and other diseases. Dairy farmers can implement heightened biosecurity measures to protect their herds. Learn more from the following resources:
- Enhanced Biosecurity Resources for Producers | Secure Milk Supply
- Farm Biosecurity | MN Board of Animal Health
- Biosecurity recommendations for H5N1 for Animal Health Officials, Veterinarians, and Producers | USDA APHIS
Testing for Interstate Movement and Reporting Requirements
In April 2024, the USDA announced a Federal Order requiring testing for and reporting of H5N1 in certain dairy cattle. This order remains in effect. More information can be found online at Federal Orders | Animal and Plant Health Inspection Service.
Mandatory Testing for Interstate Movement of Dairy Cattle
- Prior to interstate movement, dairy cattle are required to receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory.
- Owners of herds in which dairy cattle test positive for interstate movement will be required to provide epidemiological information, including animal movement tracing.
- Dairy cattle moving interstate must adhere to conditions specified by APHIS.
Mandatory Reporting
- Laboratories and state veterinarians must report positive Influenza A nucleic acid detection diagnostic results (e.g., PCR or genetic sequencing) in livestock to the USDA APHIS.
- Laboratories and state veterinarians must report positive Influenza A serology diagnostic results in livestock to USDA APHIS.
Milk and Dairy Product Safety
There continues to be no concern about the safety of the commercial milk supply because products are pasteurized before entering the market. Pasteurization has continually proven to inactivate bacteria and viruses, like influenza, in milk. Any milk entering commerce for human consumption is required to be pasteurized.
Additionally, dairies are required to send only milk from healthy animals into processing for human consumption. Because milk from impacted animals looks abnormal, it is discarded and does not enter the human food supply.
People should not prepare or eat uncooked or undercooked food, such as unpasteurized (raw) milk or raw cheeses, from animals with suspected or confirmed H5N1 virus infection. Raw milk or unpasteurized dairy products may contain harmful bacteria or viruses and can cause illness. The MDA will not allow sales of raw milk direct to consumers from farms whose herds are confirmed infected. This milk would be considered adulterated under MINN. STAT. 32D.19.
Farm Worker Safety
The CDC considers the human health risk of H5N1 for the general public low. However, people with close or prolonged, unprotected exposures to infected birds or other animals (including livestock), or to an environment contaminated by infected birds or other animals, are at greater risk of infection. To learn more, visit the CDC’s Information for Workers Exposed to H5N1.
Farmers can request PPE from the Minnesota Department of Health.
Farm Stress and Mental Health
The MDA has resources and programs available to farmers experiencing stress and mental health concerns. Find out more information on our Coping with Farm and Rural Stress web page.
H5N1 in Dairy FAQ
Biosecurity will be the most effective method to protect your animals. Minimize access of wild birds to cattle and their environment.
- Manage the movement of cattle and their transport as much as possible.
- Do not feed unpasteurized colostrum or milk to calves, cattle, or other mammals.
- Implement precautions for caretakers and veterinary teams handling sick cows, sick or dead birds, small mammals, and unpasteurized milk.
- Separate (quarantine) all new or returning animals for at least 21 days.
- Contact your herd veterinarian if increased cow illness is observed in your herd, specifically in second lactation or greater cows that are 150 days or more in milk.
Wild birds, wild animals, poultry, dairy cattle, and newborn goats have tested positive for H5N1 in Minnesota.
Infections in cattle have been traced back to infected wild birds. Research is continuing on the transmission route between animals. The newborn goat kids that were diagnosed in Minnesota shared a water source with infected poultry that had been depopulated at the same site.
Sick cattle are typically isolated and recover. Depopulation of cattle is not recommended. Milk from sick cows is diverted from the food supply. Pasteurized milk is safe to drink.
Minnesota Department of Agriculture communicates and works closely with the University of Minnesota, Minnesota Department of Health, Minnesota Board of Animal Health, United States Department of Agriculture, Veterinary Diagnostic Laboratory, and industry partners to share information and develop plans to be best prepared.
Wear clean boots or boot covers, clean clothing, wearing disposable gloves, and safety goggles. For additional guidance see the Centers for Disease Control and the Minnesota Department of Health.
- Poultry questions should be directed to the Minnesota Avian Influenza hotline 1-833-454-0156.
- The Department of Natural Resources is addressing sick and dead wild bird reports, contact local DNR wildlife staff or the DNR information center at 888-646-6367.
- Any other diseases contact the Minnesota Board of Animal Health: 651-296-2942 or your district veterinarian (business hours).
- Human health questions can be directed to the Minnesota Department of Health: call 651-201-5414.
- Milk and food safety concerns can be directed to the Minnesota Department of Agriculture at 651-201-6300.
- Biosecurity Assessments and deterrent options are available through the USDA APHIS wildlife services: Jason Gilsdorf or any wildlife services personnel for assistance at 612-271-5119 or Jason.M.Gilsdorf@usda.gov
According to the CDC, human infections with avian influenza A viruses can happen when enough virus gets into a person's eyes, nose, or mouth or is inhaled. Raw milk from infected cattle can carry the virus and make people sick. People should not prepare or eat uncooked or undercooked foods, such as unpasteurized (raw) milk, or raw milk products, from animals with suspected or confirmed Avian Influenza A (H5N1) infection.
