Board of Animal Health: H5N1 continues; mandatory milk testing to start as poultry, dairy and human detections persist

Dr. Brian Hayes, state veterinarian and executive director of the Minnesota Board of Animal Health, told the Senate committee on Jan. 22 that highly pathogenic avian influenza (HPAI/H5N1) remains active in Minnesota and the nation and that the board is preparing for expanded dairy surveillance as a mandatory national milk-testing strategy rolls out.

"This virus is not going away," Hayes said, describing a string of poultry and dairy detections since 2022 and noting a new detection in Wadena County earlier in the week. He told senators the board and the Minnesota Department of Agriculture will begin a stage-2 milk-testing approach in the first week of February and that pasteurization remains an effective control for milk entering commercial processing.

Key points from Hayes and the board briefing

- Current detections and scope: Hayes said Minnesota's most recent poultry detection (announced Jan. 21, 2025) prompted depopulation at a turkey flock. He updated the committee from 11 to 12 recent poultry premises and reported 8 commercial and 4 backyard premises among recent detections. Hayes also said Minnesota identified nine dairy-farm detections of H5N1 during the summer of 2024.

- Dairy testing and movement rules: Hayes and the Department of Agriculture described a U.S. mandatory national milk-testing strategy and said Minnesota will begin testing bulk-tank milk (stage 2) in early February. The board and Department will work through an incident-management response with quarantine authority and permitted milk movement only to pasteurization facilities when a farm tests positive. "Pasteurization is very effective at killing this virus," Commissioner Tom Peterson added.

- Human and companion-animal risk: Hayes noted about 30-plus human detections reported nationally and cited a recent fatal human case in Louisiana; most human detections have been in people with direct contact with sick animals. He warned that cats are particularly susceptible; the board described incidents where sanctuaries and domestic cats were infected, including links to raw pet food in other states. Hayes said conjunctivitis is the most common human clinical sign observed to date, with a few severe respiratory cases reported.

- Avian metapneumovirus (AMPV) and differential diagnosis: Hayes described an ongoing AMPV problem in poultry, reporting roughly 871 AMPV-positive tests since 2024. Because AMPV can mimic avian influenza clinically, producers test for HPAI first and, if negative, often find AMPV as the cause.

- Resource and funding strain: Hayes said board staff spent nearly 9,000 hours on HPAI response activities in 2024, including about 1,100 overtime hours, and warned that about 20% of the board's funding is federal and that federal cuts have reduced USDA and APHIS assistance. He said an ongoing, multi-year response tempo — with repeated outbreaks and narrower federal support — is creating personnel strain and response fatigue.

- Vaccines and trade constraints: Hayes said vaccine candidates exist for poultry but noted that influenza vaccines are strain-specific and that international-trade rules and export considerations constrain vaccine use in production animals. He said vaccine work and limited research trials in dairy cattle are under way in Minnesota.

Why this matters: cross-species spread and seasonality

The board and department told senators to expect heightened surveillance as spring migration resumes; both agencies warned of the potential for poultry and dairy cases to overlap during migration and urged producers to maintain strict biosecurity. Officials emphasized that pasteurization and proper cooking mitigate consumer food-safety risk from infected animals, but they said human infections and changes in viral behavior remain closely watched by the Department of Health, Centers for Disease Control and federal partners.

Ending

Hayes and Commissioner Peterson asked legislators to consider sustained funding and federal coordination to maintain surveillance, laboratory capacity and emergency response capabilities. The board flagged the possibility of additional resource requests if the virus remains active through migratory seasons.