Minnesota Gov. Mark Dayton declared a peacetime emergency Thursday to deal with the growing avian influenza attacking turkey flocks across dozens of farms.

At least 2.6 million birds — many at farms tied to Hormel Foods Corp. — already have been killed to stop the highly infectious virus from further devastating Minnesota poultry.

“Obviously, we’re worried. There’s no question about it,” said Minnesota Agriculture Commissioner Dave Frederickson.

The magnitude of the flu outbreak has caused the unprecedented reaction of a peacetime emergency for an agricultural disease. The flu already has been found in 46 farms in 16 Minnesota counties and has attacked almost one-fifth of the turkey stock now in the state since March. As of Tuesday, it had affected 2.3 million birds at farms with ties to Hormel subsidiary Jennie-O Turkey Store.

When a farmed bird is found to have the flu, the flock is killed as a precaution.

“It continues to grow,” Dayton said as he announced the state of emergency. The flu also has hit a large chicken producer in Iowa and may have spread to commercially grown chickens in Minnesota.

Dayton and U.S. Agriculture Commissioner Tom Vilsack, a former Iowa governor, have personally discussed the Minnesota outbreak and reactions.

The governor also is planning to visit hard-hit Willmar over the weekend to meet with turkey farmers and federal officials to discuss the issue.

The impact in Minnesota, the top turkey-producing state in the nation, has shaken farmers, devastated flocks and caused Hormel to warn that its Jennie-O Turkey Store was experiencing supply problems.

“We are experiencing significant challenges in our turkey supply chain due to the recent HPAI outbreaks in Minnesota and Wisconsin,” Hormel CEO Jeffrey Ettinger said in a press release Monday.

The five-day peacetime emergency allows state agencies, including the Minnesota National Guard, to work together to offer what help, technical assistance and relief they can to curtail the outbreak. The state’s executive council will be asked to extend it for another month next week.

Already, more than seven dozen state staffers and 134 U.S. Department of Agriculture staffers are on the ground to assess and deal with the problem.

The scope and seriousness of the outbreak are rare. The U.S. Department of Agriculture said that there have been only three similarly pathogenic flu outbreaks in commercial poultry — in 1924, 1983 and 2004.

Recently, at least 12 states have found birds with the avian flu strain, known as H5N2, including Minnesota’s neighboring states but also as far away as Oregon.

On Monday, Wisconsin Gov. Scott Walker declared a flu-related emergency in that state, which allowed the National Guard to assist in cleanup and containment.

Minnesota officials said Minnesota National Guard members will not necessarily be needed on the ground here, but their expertise and equipment may be tapped to help.

Steve Olson, executive director of the Minnesota Turkey Growers Association and Chicken and Egg Association of Minnesota, said the growers were grateful for the state’s reaction.

“Together with the poultry farmers in our state, we will stop the spread of this virus and take the steps necessary to ensure the poultry industry remains vital and we provide consumers with safe, nutritious, high-quality food,” Olson said.

Minnesota legislators also have worked to free up nearly $1 million to add to federal funds to react to the flu outbreak and reimburse farmers. Lawmakers also have introduced other legislation to address the issue.

“Right now, everybody is pulling together, as it should be,” Dayton said.