August 18, 2025: Highly Pathogenic Avian Influenza (Bird Flu) Detected in a California Retail Poultry Flock in Los Angeles County
Sacramento, CA – Following an investigation by the California Department of Food and Agriculture (CDFA), the U.S. Department of Agriculture's (USDA) National Veterinary Services Laboratories (NVSL) has confirmed highly pathogenic avian influenza (HPAI) in a retail poultry flock in Los Angeles County. This is the first detection of HPAI in domestic poultry since California was self-declared HPAI free on July 20th, 2025. All national detections of HPAI in poultry can be found at: 2022–2024 Detections of Highly Pathogenic Avian Influenza (usda.gov).
California has several poultry health programs in place that prove effective in our early detection and disease monitoring strategy. This detection is an example of one of our program’s effectiveness. This particular program depends on the cooperation of select poultry owners, who volunteer to have their birds tested monthly. Through this testing program, we look for diseases of concern including virulent Newcastle disease and highly pathogenic avian influenza (HPAI). Through routine testing, we were able to confirm HPAI before sick birds were reported and our Emergency Animal Health Responders were able to act rapidly to prevent the spread. The retailer’s proactive approach for routine surveillance testing through CDFA has proved a great service to our California communities.
This HPAI virus spreads easily between birds and is lethal to poultry, so infected flocks are quarantined and euthanized, followed by cleaning and disinfection of the property. 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 the fur of rodents and other animals exposed to infected birds or cattle. The source of infection in this flock is currently unknown and under investigation. Testing of other farms will be conducted over the next several weeks to determine the extent of spread. We strongly urge all poultry owners in California to protect their flocks by increasing their biosecurity practices. Recommended biosecurity practices can be found on the CDFA and USDA websites.
Clinical signs of HPAI include sudden death, trouble breathing, clear runny discharge (from nose, mouth, and eyes), lethargy, decreased food and water intake, swelling (eyes, head, wattles, or combs), discolored or bruised comb, wattles, or legs, stumbling/falling, or a twisted neck. For more information and updates, please visit our CDFA Avian Health Program webpage. Poultry owners with flocks that have experienced any unusual/suspicious illness or deaths should call our CDFA Sick Bird Hotline at 866-922-BIRD (2473).
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 the California Department of Fish and Wildlife directly: Wildlife Health Lab - Avian Investigations (ca.gov).
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For more information and updates on wild bird detections in California, visit the California Department of Fish and Wildlife website.
For public inquiries regarding HPAI in California, please call 916-217-7517 or send an e-mail to cdfa.HPAIinfo@cdfa.ca.gov. For media inquiries, please call 916-654-0462 or send an e-mail to officeofpublicaffairs@cdfa.ca.gov.
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On July 20, 2025, the State of California completely fulfilled the necessary actions and surveillance requirements to again self-declare free from HPAI in Poultry.
As of July 20, 2025, California has self-declared as free from Highly Pathogenic Avian Influenza (HPAI) in poultry. This declaration can be made after meeting requirements established by USDA including the release of all quarantines on poultry premises and undergoing a subsequent waiting period with no additional disease detections. Active HPAI in poultry in the US impacts international exports of poultry and poultry products.
While California is declared HPAI free in our Poultry, we still have ongoing H5N1 infections in our dairy herds. H5N1 infections in dairy cattle do not affect our animal health status for exportation. California has confirmed 43 cases of H5N1 Influenza in California dairies that have been re-quarantined by CDFA after prior release. These are new detections on diaries that were infected previously but had their CDFA quarantine lifted after 3 negative whole herd tests via bulk milk tank samples, one week apart. These 43 farms have been shown to have sufficient virus present to be placed back under State Quarantine.
All dairies in the state continue to be under regular surveillance for continued monitoring of the virus in California.
Although California is disease free from HPAI in Poultry, due to the increased number of re-infections in California dairies, the Ban on all California Poultry and Dairy Cattle Exhibitions at Shows and Fairs remains in place.