Wisconsin’s first avian influenza case in a dairy herd means a change in the state’s milk testing procedure.

Adam Brock with the state’s Department of Agriculture, Trade, and Consumer Protection says Wisconsin was able to do less testing for a while. “In September of 2025, we achieved gold status, so that allowed us to reduce our frequency of testing 50%. Now that we’ve got one detection in a Wisconsin dairy herd, we are going to transition back to that 100% testing strategy as soon as possible.”

Brock says the one Wisconsin herd found to have the H5N1 virus was a surprise. “There are no clinical signs. This was caught purely through the National Milk Testing Strategy. The farmers didn’t even know there was a concern. A milk sample came it and it was tested high.”

Brock says additional tests on the Dodge County herd confirmed the presence of the virus.

The herd has been quarantined to prevent spreading the virus, but the cows are healthy.  Brock says pasteurization kills the virus, so there is no food safety issue.

Source: Brownfield Ag News / Larry Lee