Dairy Cows Infected with Bird Flu

Outbreak Spreads Across Multiple States

Multi-Agency Response Underway

The U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) has confirmed a multistate outbreak of highly pathogenic avian influenza (HPAI) A H5N1 in dairy cows.

The outbreak was first reported on March 25, 2024, and has since spread to multiple states. The U.S. Department of Agriculture Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) are working together to respond to the outbreak.

Animal challenge studies completed by the USDA have shown that HPAI A H5N1 can spread from wild birds to dairy cows.

Whole viral genome sequences recovered from dairy cows, birds, domestic cats, and a raccoon indicate that the virus is continuing to evolve.