The California Department of Food and Agriculture (CDFA) is investigating the possible introduction of the H5N1 virus at three dairy farms in the state’s Central Valley.
The agency reported that it was investigating the situation on August 29.
If confirmed, those would be the state’s first cases of H5N1 in cattle.
With the detection of H5N1 in dairies elsewhere in the United States in recent months, CDFA has been engaged with private veterinarians, farmers and ranchers, and local, state and federal partners to develop response plans and actively monitor for the disease in livestock and poultry throughout California. CDFA stated that it has taken steps to reduce the risk of entry of infected dairy cattle into the state, has maintained rapid response capability used during past detections of HPAI in poultry, and is prepared to respond to detections in cattle.
Samples from cattle at these three sites have been submitted to the California Animal Health and Food Safety (CAHFS) laboratory. Any positive tests at the California lab would be considered “presumptive” and submitted to the United States Department of Agriculture (USDA) for final confirmation.
If these cases are confirmed, CDFA will continue working closely with the California Department of Public Health, and local agricultural and public health officials, to understand the extent of the introduction and support animal health and public health activities with the goal of limiting exposure to virus while the impacted herds develop immunity.
According to the USDA Animal and Plant Health Inspection Service (APHIS), the last time the presence of H5N1 was confirmed in a commercial poultry flock in California was January 18, involving a layer pullet flock in Merced County.
More recently, the virus was confirmed present at a live bird market in San Francisco County on May 9. However, highly pathogenic avian influenza (HPAI) cases in live bird markets, such as that one, should not have an impact on poultry trade, in accordance with World Organisation for Animal Health (WOAH) standards.
During the past 30 days, according to APHIS, the presence of H5N1 has been confirmed in dairy cattle in the following states: Idaho, Colorado, South Dakota, Michigan and Texas.
