Highly Pathogenic Avian Influenza

Chickens in chicken coop

Dec. 6, 2023 - Following an investigation by the California Department of Food and Agriculture (CDFA) and rapid disease detection by California Animal Health and Food Safety Laboratory System (CAHFS), the U.S. Department of Agriculture’s National Veterinary Services Laboratories (NVSL) has confirmed highly pathogenic avian influenza (HPAI) in commercial flocks in Stanislaus County. This is in addition to the recent cases during this year’s fall bird migration in the following four counties: Fresno, Merced, San Benito, and Sonoma.

To protect other flocks in California, the locations of the detected infected flocks are currently under quarantine, and the birds are euthanized to prevent further disease spread.

According to the Centers for Disease Control and Prevention (CDC), this strain is considered a low risk to human health, however, avian influenza is a highly contagious and often fatal disease in birds. The disease is spread through movement of infected or exposed birds, direct or indirect contact with infected wild and domestic birds or contact with virus on fomites (surfaces) such as hands, shoes, clothing, or feet and fur of rodents and other animals.

According to the Centers for Disease Control and Prevention, the current detections of HPAI in birds does not present a public health concern and the public health risk remains low. While not recommended, if you handle sick or dead wild birds, use disposable gloves (or a plastic bag turned inside out) to place the body in a garbage bag. No birds or bird products infected with HPAI will enter the food chain. As a reminder, it is recommended that all poultry and eggs are properly handled and cooked to an internal temperature of 165 ˚F as a food safety precaution. Please contact your local public health department for further information on preventing avian influenza in people. 

Avian influenza is a highly contagious and often fatal disease in birds. We are urging poultry owners to increase their biosecurity practices. Biosecurity is the measures taken to prevent disease from entering and/or leaving a premises or location. Although this outbreak of avian influenza is primarily being spread by wild birds, the virus can be further spread between domestic flocks through contact with infected poultry, from contaminated equipment, and even the shoes and clothing worn by poultry caretakers.

Biosecurity recommendations to protect backyard poultry flocks:

  • Wash your hands before and after handling your birds. This includes when handling birds from coop to coop.
  • Prevent contact between domestic and wild birds by bringing your birds into an enclosure that is covered.
  • If you have bodies of water on your property such as ponds or ditches, consider draining them to avoid attracting wild birds, and keep your domestic birds away from this potentially contaminated water.
  • Use sanitized well or city water for your birds.
  • Prevent rodents and predators from entering your coop.
  • Prevent pets such as cats and dogs from eating dead wild birds.
  • Keep feed covered and spills cleaned up to avoid attracting wild birds and rodents.
  • Wash and disinfect boots and equipment when moving between coops.
  • Do not share equipment or supplies with neighbors.
  • Clean and disinfect equipment and other supplies between uses.
  • Clean and disinfect your shoes and vehicle tires after visiting feedstores and other places frequented by other poultry owners or wild bird hunters.
  • Avoid visiting places where wild birds congregate such as lakes and ponds.

Report any unusual or suspicious numbers of sick or dead domestic birds immediately to the CDFA Sick Bird Hotline at (866) 922-2473

Monitor your birds for the following symptoms:
  • Trouble breathing
  • Clear, runny discharge from nose, mouth, and eyes
  • Lethargy or lack of energy
  • Loss of appetite
  • Drinking less
  • Swollen eyes, head, wattles, or combs
  • Discolored or bruised comb, wattles, or legs
  • Stumbling, falling, or twisted neck
  • Sudden death

Stay Alert

Report any unusual or suspicious dead wild birds to the California Department of Fish and Wildlife online. If you have questions about wildlife rehabilitation, please contact California Department of Fish and Wildlife directly. Contact information is available here: Wildlife Health Lab - Avian Investigations (ca.gov)  

For general public inquiries regarding highly pathogenic avian influenza in California, please call: 916-217-7517. 

For media inquiries, please call 916-654-0462 or send an e-mail to: [email protected]. 

Stay Informed  

For the latest updates in California domestic poultry, follow CDFA on social media and subscribe - on Facebook at Animal Health Branch – CDFA and on Instagram at AnimalHealthBranch_CDFA.  

For more information and updates on wild bird detections in California, visit the California Department of Fish and Wildlife website.   

More information on avian influenza and how to protect flocks through biosecurity measures can be found on the U.S. Department of Agriculture’s website.