Bird flu has infected a Benton County dairy herd this week, marking the first confirmed detection of the virus in cows in Minnesota.

But per State Veterinarian Dr. Brian Hoefs, “it was only a matter of time.”

“It’s important for dairy farmers to follow the example of this herd and test sick cows,” Hoefs said in a Thursday statement. “The more the animal health community can learn about this virus today through testing and research, the better we can equip ourselves to prevent infections tomorrow.”

Several dozen cows are sick. Farmers will destroy milk from the animals, and the cows will quarantine for 30 days, according to the Minnesota Board of Animal Health.

The board said public risk from avian influenza is currently low, though “people who work with or have direct contact with infected animals could be at risk of getting sick.”

A dairy worker in Texas contracted bird flu this past March and recovered. Only one other person in the U.S., a poultry worker in Colorado, is known to have caught the virus during the current outbreak that began two years ago.

“Symptoms of avian influenza in people may include cough, sore throat, fever, red/watery eyes or discharge from the eyes,” according to the board.

The U.S. Food and Drug Administration said this spring it found inactive traces of the virus in the milk supply, but health officials said pasteurized dairy remains safe.

“There continues to be no concern that this circumstance poses a risk to consumer health, or that it affects the safety of the interstate commercial milk supply because products are pasteurized before entering the market,” the FDA said.

The cow cases come amid a resurgence in bird flu infections at Minnesota poultry operations, including the euthanizing of tens of thousands of turkeys and more than 1.3 million egg-laying hens last month. That pushed the state’s virus-related poultry losses to nearly 8 million since 2022.

The virus’ movement to cattle and other mammals has occurred in several states. Cows are able to survive the infection, unlike chickens and turkeys.

State officials are urging dairy farmers to contact their veterinarian if cows appear sick. Symptoms include fever, lower milk production, loss of appetite and changes in manure consistency, the board said.