U.S. Department of Agriculture (USDA) has confirmed highly pathogenic avian influenza (HPAI) in dairy herds in nineteen states. The confirmations were made via milk samples as well as nasal swabs and viral genome sequencing of the affected herds. USDA confirmed that the detections in dairy cows appear to have been introduced by wild birds; however, the Department continues to conduct an epidemiological investigation into how the virus is being transmitted among dairy herds and, so far, has no conclusive evidence. The latest USDA report on disease spread between dairy cattle farms found multiple direct and indirect transmission routes.
The USDA, CDC, and FDA continue to affirm that milk and dairy products remain safe to consume and the threat to the public remains low. The FDA and USDA co-signed letters to dairy processors and retailers emphasizing the confidence that the U.S. government has that pasteurization is effective in inactivating H5N1 in raw milk just as it is for pathogens against which we began pasteurizing raw milk 100 years ago. Pasteurization (high heat treatment) kills harmful pathogenic bacteria and other microorganisms, including viruses inclusive of HPAI. Routine testing and well-established protocols for U.S. dairy also continue to ensure that only safe milk enters the food supply.
The U.S. Centers for Disease Control and Prevention (CDC) has confirmed 41 human cases of HPAI virus infection with an exposure source of dairy cattle in the United States in 2024 and 2025.
The latest news and resources from the coordinated U.S. government response to the illness is available here. More information related to milk and dairy safety, the virus, U.S. dairy biosecurity measures, workplace safety and protection, customer messaging, and more is located below.