USDA expands milk testing
Because H5N1 bird flu is advancing, the USDA has launched a National Milk Testing Strategy to screen dairy herds, and reporting says roughly 10 million birds were affected in the past month — a move aimed at protecting the food supply. (Researchers are also testing containment tools: Purdue is developing an anti‑viral fogging system using a natural oil compound for poultry facilities to slow airborne and surface spread.) (dvm360.com) (rfdtv.com)
Bird flu is no longer just a chicken problem. Since March 25, 2024, the Centers for Disease Control and Prevention says the same Highly Pathogenic Avian Influenza H5N1 virus has been found in dairy cows, which means one outbreak is now crossing between bird barns and milking parlors. (cdc.gov) Milk testing works like a smoke alarm for a herd. Purdue’s veterinary guidance says the virus can be shed in milk at high concentrations, so a sample from a bulk tank can reveal an infected dairy before every cow on the farm is individually tested. (purdue.edu) That is why the United States Department of Agriculture started a National Milk Testing Strategy on December 6, 2024. The Animal and Plant Health Inspection Service said the program is built around testing bulk milk and using a five-stage system that starts with silo sampling and can move to long-term proof that a state is free of the virus. (usda.gov) (govdelivery.com) The rollout got much bigger on January 17, 2025, when six more states joined. Reporting that quoted the Department of Agriculture said 36 states were then participating, covering bulk milk tank samples from about two-thirds of United States dairy herds and nearly three-quarters of United States milk production. (global-agriculture.com) (michiganfarmnews.com) The government is using milk because pasteurization and herd surveillance solve different problems. Pasteurization kills the virus in commercial milk for people to drink, while raw milk testing tells officials where infected cows are so they can limit animal movement and keep the outbreak from hopping to more farms. (cdc.gov) (usda.gov) The poultry side is still getting hit hard at the same time. Purdue Extension says the national outbreak had already cost more than $1.4 billion by November 2024, and Indiana alone recorded more than 8.5 million affected poultry birds between February 2022 and March 2025. (purdue.edu) One reason this keeps spreading is that the virus can move through barns in more than one way. Purdue’s avian influenza guidance says Highly Pathogenic Avian Influenza strains can wipe out entire poultry flocks within days, and current livestock guidance says spilled raw milk, equipment, vehicles, and other contaminated materials can help carry H5N1 from place to place. (purdue.edu 1) (purdue.edu 2) That is where the new fogging research comes in. Radio Frequency Data Television reported on April 9, 2026 that the Department of Agriculture is putting $2 million into a Purdue-led project to test an antiviral fog inside poultry houses that targets virus particles in the air and on surfaces. (rfdtv.com) The compound in that fog is hydrogenated catmint oil, which is a processed plant oil related to catnip. Purdue’s research partners say the project will test whether aerosolized doses can disrupt influenza virus at very low concentrations, check safety in chickens, and measure whether the system works under real poultry-house conditions. (prnewswire.com) (thepoultrysite.com) So the federal response is splitting into two tracks. One track samples milk to find infected dairy herds early, and the other tries to knock virus out of poultry buildings before it can spread through a flock or hitch a ride to the next farm. (usda.gov) (rfdtv.com)
