Ohio leads the nation in recent bird flu cases among commercial poultry operations, with more than 4.1 million chickens and turkeys affected so far this year.

The first case of bird flu on a farm in Pennsylvania in 2025 was detected on a poultry farm in Lehigh County on Monday, the state's Department of Agriculture announced.

More than two million birds in the Miami Valley have been “depopulated” due to highly pathogenic avian influenza. The Ohio Department of Agriculture reported 2,052,773 birds have been “depopulated” in the Miami Valley because of H5N1 since Jan.

The government is investigating a rare strain of avian flu, H5N9, detected on a duck farm in central California, according to the World Organisation for Animal Health. It marks the first reported outbreak of this strain in U.

Bird flu infections around the U.S. have forced mass cullings and resulted in the deaths of zoo animals and pets