HPAI in Livestock | Animal and Plant Health Inspection Service

The U.S. Department of Agriculture (USDA), Food and Drug Administration, Centers for Disease Control and Prevention, and State veterinary and public health officials are investigating cases of highly pathogenic avian influenza (HPAI) in dairy cows.

USDA has been responding, in collaboration with State officials, to HPAI H5N1 detections in U.S. poultry since February 2022. After the first detection of HPAI H5N1 in dairy cattle in March 2024, USDA has worked swiftly and diligently to assess the prevalence of the virus in the U.S. dairy herds and respond accordingly. See Where HPAI Has Been Confirmed in Dairy Herds

The best way to keep the virus off your farm and reduce any potential impacts is to follow biosecurity best practices on your farm. Simply put, biosecurity refers to everything people do to keep disease away from animals, property, and people.

USDA will reimburse dairy producers for planning and implementing enhanced biosecurity practices.

On April 24, 2024, USDA announced a Federal Order (149.89 KB) mandating testing prior to the interstate movement of lactating dairy cattle and mandating reporting of positive influenza A test results in livestock.

One way to meet the restrictions is to enroll in the Dairy Herd Status Program. This voluntary program offers dairy producers the option to monitor their herds via a weekly bulk milk sample before moving them across State lines—without having to test each individual animal.

If you suspect a possible HPAI infection on your farm:

Contact USDA for more help preventing or responding to an HPAI infection on your farm.

The Dairy Herd Status Program and financial assistance to enhance biosecurity and offset costs associated with Influenza A testing are available to all dairy producers.

In addition, USDA offers the following assistance for affected dairy producers to offset costs and losses:

Learn More About Financial Assistance

Below are answers to a few key questions about the detection of HPAI in dairy herds. To see more, download Detection of HPAI H5N1 in Dairy Herds: Frequently Asked Questions (420.81 KB).

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.

Since the initial detection of HPAI in dairy cattle, USDA has worked quickly and in concert with our Federal and State partners to better understand, mitigate the risk of spread, and contain the virus. USDA experts and Federal partners also took swift action to trace animal movements, assess the disease prevalence in herds, initiate a variety of testing activities to confirm the safety of the meat and milk supplies, and roll out numerous support programs for dairy producers.

The evidence to date points to a single spillover event in Texas in March 2024 and shows that continued transmission is largely due to the interstate and regional movement of livestock, people, and equipment. In response, USDA is working closely with producers to eliminate this disease in U.S. dairy herds through enhanced surveillance and biosecurity measures.

Undoubtedly, the presence of H5N1 on dairy farms can bring uncertainty and the potential for economic challenges for U.S. farm owners, workers, and dairy processors. USDA has implemented or expanded a number of programs to support affected dairy premises. These include the Dairy Herd Status Program and financial assistance for the heat treatment and disposal of milk, veterinary costs, personal protective equipment (PPE), milk loss offset via the Emergency Livestock Assistance Program (ELAP), biosecurity planning and implementation, as well as shipping cost offset for H5N1 testing.

Learn More About These Programs

While the current public health risk is low, CDC, in partnership with USDA and other Federal agencies, is watching the situation carefully and working with States to monitor people with animal exposures.

Learn More About the CDC’s Flu Surveillance Systems and HPAI Activity in People

If you have questions or want to enroll in any of USDA's support programs for producers, contact your State animal health official or APHIS Area Veterinarian in Charge.

Find Your Area Veterinarian in Charge