September 10, 2025

After four straight months of testing raw milk samples from Minnesota cow dairy farms for the avian influenza A (H5N1) virus without any detections, the U.S. Department of Agriculture (USDA) has changed Minnesota’s status from Affected to Unaffected in their National Milk Testing Strategy (NMTS).

That means that the Minnesota Department of Agriculture (MDA) will reduce how frequently it tests milk samples from once a month to approximately once every two months. Federal restrictions on animal movement between states remain in effect.

In February 2025 the MDA, in cooperation with the Minnesota Board of Animal Health (BAH), joined the NMTS to begin conducting H5N1 virus surveillance and prevent its spread to unaffected dairy herds and poultry flocks.

“We and the Board are extremely grateful for the dairy industry’s cooperation in achieving this important milestone and for supporting the health and vitality of Minnesota’s livestock and poultry industries,” MDA Commissioner Thom Petersen said.

After one case of H5N1 was detected in a dairy herd in March, there have been no other Minnesota detections. The USDA approved Minnesota’s status change on August 22.

The MDA may further reduce testing frequency if results continue to show no detections through the fall, but continued monitoring is required until all 50 states have reached Unaffected Status.

Dairy farmers don’t have to do anything to help with sampling or testing, as they are done in cooperation with industry laboratories who routinely test for other purposes.

While H5N1 is still an emerging disease in dairy cattle, most affected herds in the U.S. have fully recovered. This is good news for the dairy industry, but H5N1 remains deadly in poultry and capable of causing human illness. It is important to prevent the spread of the virus whenever it is detected in livestock animals.

If tests detect H5N1 in a dairy herd, the MDA or BAH assigns a case manager to guide the farm through the response, which includes a quarantine period and follow-up testing.

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Media Contact
Larry Schumacher, MDA Communications
651-201-6629
Larry.Schumacher@state.mn.us