The U.S. Department of Agriculture (USDA), Food and Drug Administration (FDA), Centers for Disease Control and Prevention (CDC), and State veterinary and public health officials are working together to protect livestock, farms, and communities from avian influenza.
Our Response to Avian Influenza
- Testing
Producer Support Programs
Get the Facts
Below are answers to a few key questions about the detection of HPAI in dairy herds.
HPAI is a very contagious and often deadly respiratory disease of poultry, such as chickens, turkeys, and geese. It is often spread by wild birds and can make other animals sick, too. It's a major threat to the poultry industry, animal health, trade, and the economy worldwide. Caused by influenza type A viruses, the disease varies in severity depending on the strain and species affected.
HPAI H5N1 viral infection was first confirmed on a dairy premises on March 25, 2024. USDA, in coordination with States, took immediate action to conduct additional testing for HPAI, as well as viral genome sequencing, to learn more about the virus and how it was spreading among dairy cattle. USDA and State teams conducted extensive epidemiological work to investigate the links between HPAI-affected dairy premises and evidence of spillover into poultry premises.
Continued disease transmission regionally within the country is due to several factors. In addition to the movement of livestock, transmission between farms is likely related to normal business operations such as numerous people, vehicles, and other farm equipment frequently moving on and off an affected premises and on to other premises. Importantly, it is not currently believed that the disease is spread onto dairy or poultry premises by migratory waterfowl—this is supported by both genomic and epidemiological data analysis.
HPAI is extremely deadly in poultry flocks and can wipe out entire flocks within a matter of days. There is no treatment for HPAI. In poultry, the only way to stop the disease is to depopulate all affected and exposed poultry.
While dairy herds can show clinical signs of infection (such as reduced milk production; thicker, concentrated, colostrum‐like milk; a decrease in feed consumption; abnormal tacky or loose feces; lethargy; dehydration; and fever) most dairy cows are able to recover.
If you suspect a possible HPAI infection on your farm:
- Report it! Isolate any sick or exposed animals and contact your veterinarian, State animal health official , or the APHIS Area Veterinarian in Charge.
- Monitor yourself and your workers for new respiratory illness symptoms, including conjunctivitis (eye redness), for 10 days after exposure. This includes people who have worn recommended personal protective equipment.
- Those who develop symptoms should seek prompt medical evaluation for possible influenza testing by their clinician or public health department.
Testing for HPAI H5N1 is crucial to achieve disease freedom from this virus in U.S. dairy cattle. USDA works closely with Federal, State, and industry partners to ensure our testing activities are comprehensive.
APHIS provides all H5 livestock testing through the National Animal Health Laboratory Network (NAHLN) and National Veterinary Services Laboratories (NVSL), free of charge. We receive samples via many efforts and programs:
- Milk testing per the December 2024 Federal Order and National Milk Testing Strategy
- Testing prior to interstate movement under the April 2024 Federal Order
- Dairy Herd Status Program
- Testing programs that some States have designed pursuant to their unique authorities
- Testing prior to interstate movement to fairs, exhibitions, or sales as part of State testing programs
- For producers interested in learning the status of their livestock herds
We use test results to better identify the prevalence of the virus and guide response steps nationwide.