In a joint effort, the U.S. Department of Agriculture (USDA), Food and Drug Administration (FDA), and Centers for Disease Control and Prevention (CDC) are actively investigating an illness affecting dairy cows across several states. The cows are exhibiting symptoms such as decreased lactation, low appetite, and other related issues.

On March 25, two dairy herds in Texas and two dairy herds in Kansas were confirmed to have contracted highly pathogenic avian influenza (HPAI). Subsequently, the USDA's National Veterinary Services Laboratories (NVSL) discovered the presence of HPAI in a Michigan dairy herd, which had recently received cows from Texas. Presumptive positive test results for additional herds in New Mexico, Idaho, and Texas have also been received, pending confirmation by NVSL.

The NVSL has reported that the strain of the virus found in Michigan resembles the one detected in Texas and Kansas, suggesting a potential introduction by wild birds. However, initial testing has not revealed any changes in the virus that would make it more transmissible to humans. While cases of human infection are possible through direct contact with infected animals, the current risk to the public remains low.

The spread of symptoms among the Michigan dairy herd indicates the possibility of HPAI transmission between cattle. As a result, the USDA and its partners are closely monitoring the situation and have advised veterinarians and producers to implement strict biosecurity measures, conduct animal testing when necessary, minimize animal movements, and isolate sick cattle from the rest of the herd.

Despite the affected animals' recovery after isolation, the safety of the commercial milk supply remains unaffected. All milk products undergo pasteurization before entering the market, and any milk from impacted animals is diverted or destroyed to prevent its entry into the human food supply. Over the years, pasteurization has proven effective in inactivating bacteria and viruses, including influenza, in milk. Therefore, there is no immediate concern about the risk posed to consumer health.

In light of the HPAI detections, the FDA is reminding consumers of the potential dangers associated with consuming raw, unpasteurized milk. The FDA strongly advises against the production and sale of raw milk or raw/unpasteurized milk cheese products made from milk obtained from cows showing symptoms of illness or exposure to avian influenza.

Currently, the loss of milk production due to symptomatic cattle is limited and expected to have minimal impact on supply and pricing. The United States typically experiences an ample milk supply during the spring months due to increased production levels.

Federal agencies, in collaboration with state and industry partners, are urging farmers and veterinarians to promptly report any cases of cattle illness. By doing so, potential additional cases can be monitored, and the impact and risk to farmers, farmworkers, consumers, and other animals can be minimized. Enhanced biosecurity measures are being recommended to prevent further spread.

The USDA continues to work diligently, transforming America's food system with a focus on resilient local and regional food production, fair markets for all producers, and ensuring access to safe, healthy, and nutritious food in all communities. The department is also committed to equitable practices, removing systemic barriers, and creating a more representative workforce.

For more information, visit the official USDA website at www.usda.gov, where updates on the investigation and precautionary measures can be found.