Dairy farmers in Minnesota are on high alert for avian influenza, as cows in a growing number of states become infected.

The cases confirmed by the U.S. Department of Agriculture last week mark the first known cases of bird flu in cattle.

Health officials have now confirmed the detection of the virus in dairy herds in Texas, Kansas, Michigan, New Mexico and Idaho.

“The fact that it is in cattle now definitely raises our concern level,” said Dr. Mandy Cohen, the director of the Centers for Disease Control and Prevention. “And we have some work to do to better understand that.”

Minnesota is home to nearly half a million dairy cows, according to the most recent report from the National Agricultural Statistics Service, and ranks seventh in the country for milk production.

“It’s unusual. We need to monitor it,” said Joe Armstrong, a veterinarian and cattle production systems educator with the University of Minnesota Extension.

When asked if bird flu could spread to cows in Minnesota, he responded: “I would be surprised if it’s not here already.”

Armstrong said, so far, the infected cows in other states are not dying from bird flu but they are getting sick for days at a time.

“The cows are not eating as much as they should. Because they’re not eating, they’re not milking, they don’t produce as much milk,” Armstrong explained. “In the most severe cases, we’re seeing that the milk is actually abnormal. It doesn’t look like normal milk. That milk never enters the food supply.”

The USDA posted this update this week, which includes more information about the safety of milk:

“There continues to be no concern that this circumstance poses a risk to consumer health, or that it affects the safety of the commercial milk supply because products are pasteurized before entering the market. Dairies are required to send only milk from healthy animals into processing for human consumption; milk from impacted animals is being diverted from the commercial milk tank or destroyed so that it does not enter the human food supply. In addition, pasteurization has continually proven to inactivate bacteria and viruses, like influenza, in milk. Pasteurization is required for any milk entering interstate commerce for human consumption. FDA’s longstanding position is that unpasteurized, raw milk can harbor dangerous microorganisms that can pose serious health risks to consumers, and FDA is reminding consumers of the risks associated with raw milk consumption in light of the HPAI detections.”

Federal agencies do not expect the overall milk supply to be impacted or for milk prices to go up because of the developing situation with avian influenza among cattle.

“I think the biggest thing is that this is a financial and animal health concern for dairy farmers,” said Lucas Sjostrom, a dairy farmer in Stearns County.

Sjostrom runs Jer-Lindy Farms, which has about 200 dairy cows.

He said losing milk from sick cows has the potential to hurt farmers who are already dealing with thin margins.

“It’s thinking about strategy, it’s thinking about challenges, thinking about opportunities,” Sjostrom said. “This is a new development for us that we’re unfortunately going to need to learn a little more poultry science, a little more avian science than we used to know as we move forward.”

The Centers for Disease Control and Prevention notes the overall risk of bird flu in people remains low.

So far, one person in the United States has tested positive for the virus, after coming into contact with infected dairy cattle in Texas. The patient reported eye redness consistent with conjunctivitis as their only symptom and is recovering. It is believed to be the first instance of likely mammal to human transmission.

For more information from the CDC, click here.