In this week’s episode of Seen and Herd, we explore the latest developments surrounding the outbreak of highly pathogenic avian influenza (HPAI) in California’s dairy farms. Anja Raudabaugh discusses the virus’s impact on the dairy industry and the rigorous biosecurity measures in place, including what we know:

• Cows at three California dairies located in the Central Valley began showing clinical signs consistent with highly pathogenic avian influenza (HPAI) beginning August 23-25, 2024. Samples from these three sites were submitted to the California Animal Health and Food Safety (CAHFS) laboratory and found “presumptively positive” then submitted to the National Veterinary Services Laboratory (NVSL) for official confirmation. On August 30, 2024, NVSL confirmed HPAI in all three dairies. CDFA’s preliminary investigation has confirmed that cows have been moved among these dairies recently.
• No human cases of HPAI have been confirmed in California related to this incident. The California Department of Public Health (CDPH) is working in collaboration with CDFA and will work with local health departments to monitor any individuals who may be exposed to infected animals to ensure prompt clinical and public health interventions, and CDPH would provide official confirmation of any human cases associated with this incident.
• California’s supply of milk and dairy foods is safe and has not been impacted by these events. As a precaution, and according to longstanding state and federal requirements, milk from sick cows is not permitted in the public milk supply. Also, pasteurization of milk is fully effective at inactivating the virus, so there is no cause for concern for consumers from milk or dairy products. Pasteurized milk and dairy items, as well as properly handled meat and eggs, continue to be safe to consume.
• The affected dairies have been placed under quarantine on the authority of CDFA’s State Veterinarian, and enhanced biosecurity measures are in place. Sick cows are isolated and are being treated at the dairies; and healthy cows have been cleared to continue shipping milk for pasteurization.

To support producers, Western United Dairies has set up a landing page with the latest information and resources, including an order form for free personal protective equipment (PPE).

If you have questions about HPAI, please contact Anja at [email protected]. •