Bird flu found in Montcalm County dairy cows amid nationwide outbreak

Bird flu was detected in a Montcalm County dairy herd, state agricultural officials announced Friday, expanding the highly contagious disease beyond poultry in Michigan.

The affected dairy herd had recently received cattle from a farm in Texas where cows also have been infected with the virus, known as highly pathogenic avian influenza.

The Texas herd had not shown any sign of disease at the time those cows were shipped to Montcalm County, the Michigan Department of Agriculture and Rural Development said.

Bird flu also has been detected or presumed in dairy herds in Kansas, New Mexico and Idaho, the U.S. Department of Agriculture said Friday. The USDA said the strain of virus in Michigan, Texas and Kansas appears to have been introduced by wild birds, but transmission of the virus between cattle "cannot be ruled out."

The affected Montcalm County farm voluntarily stopped movement of livestock from the farm to limit spread of the disease, the agriculture department said.

In a press release, the department urged farmers to be vigilant about biosecurity amid "this national situation."

"This case does reflect a lot of what is already known about this virus — namely, that it is highly contagious, it continues to be primarily spread by wild birds and contact with infected animals, and mammals can contract the virus," State Veterinarian Nora Wineland said. "As more is learned, it is vitally important for producers to work with their veterinarian and isolate sick animals from others, minimize the number of visitors to their farms, prevent contact between their animals and wildlife, and continue to vigilantly monitor the health of their animals."

Avian influenza can be transmitted from sick birds and animals or through items that were exposed to the virus, such as feed, equipment or farmers' shoes.

It's unclear how the sick cows contracted disease, agriculture department spokesperson Chelsea Lewis-Parisio said.

The infected cows are recovering, Lewis-Parisio said. Avian influenza is often fatal to chickens and other birds.

The agriculture department said human health risk remains low because the virus from the sick cows has not shown significant changes that would make the virus more transmissible between mammals. No infected milk or meat is entering the food supply, Lewis-Parisio said.

The ongoing avian influenza outbreak hit Michigan farms in 2022. The state has issued roughly two dozen alerts about infected flocks and pets since February 2022.

ckthompson@detroitnews.com