USDA Reports — Veterinarians: What You and Your Clients Need To Know About Highly Pathogenic Avian Influenza

poultry producer handing a chicken to a veterinarian
Photo courtesy of USDA

Highly pathogenic avian influenza (HPAI) is a deadly disease of poultry. Recently, H5N1, a subtype of HPAI, was detected in wild birds and commercial and backyard poultry flocks in several U.S. States. With the increase of backyard producers and pet bird owners, the U.S. Department of Agriculture needs your help. As a companion animal veterinarian, you can help your clients protect their backyard flocks and pet birds by showing them how to recognize the signs of HPAI and urging them to report sick birds. Rapid and thorough reporting is critical to stop the spread of this disease.

What is HPAI?

Avian influenza is a respiratory disease of birds caused by influenza type A viruses. These viruses are common in wild birds in the United States and around the world. In most cases, they cause few or no signs of infection. However, some subtypes, like H5N1, can cause severe illness and death in poultry.

How does HPAI spread, and which bird species are most susceptible?

HPAI spreads quickly through direct, bird-to-bird contact. It can also be transmitted via contaminated surfaces (such as clothing, shoes, and vehicles). Wild birds can spread the virus to new areas through their feces.

Domestic poultry such as chickens and turkeys are most likely to experience severe disease and death from HPAI, with mortality rates often exceeding 90 percent. Birds of prey, ratites, and psittacines are also susceptible to HPAI infection.

What are the signs of HPAI?

The most common signs of HPAI include sudden death, decreased food and water consumption, lethargy, respiratory distress, nasal discharge, purple discoloration or swelling around the legs and head, a drop in egg production, and diarrhea.

What can your clients do to keep their birds safe?

There is no cure for HPAI. Good biosecurity is the key to keeping poultry safe. Urge your clients to:

  • Keep wild birds and rodents out of poultry houses and coops and away from backyard flocks and pet birds.
  • Secure feed bins and water and consider removing bird feeders to avoid attracting wild birds.
  • Keep visitors away from birds and avoid visiting other poultry farms or other people’s birds.
  • Wash hands and scrub boots before and after entering a poultry area. Wear disposable boot covers and coveralls, if possible. If you’ve been in areas frequented by waterfowl, change clothes and shoes before handling poultry.
  • Isolate new birds or those returning from shows for 30 days before introducing them to the flock.
  • Immediately report sick birds to your State Veterinarian or call USDA at 1.866.536.7593.


To learn more about HPAI, go to and search “avian influenza.” For more biosecurity tips, go to and search “defend the flock.” For information about avian influenza and human health, visit the Centers for Disease Control and Prevention website.

Immediately report sick birds to your State Veterinarian or call USDA at 1.866.536.7593.