The U.S. Department of Agriculture (USDA), Food and Drug Administration (FDA), and Centers for Disease Control and Prevention (CDC) are investigating an illness affecting older dairy cows in Texas, Kansas, and New Mexico. Unpasteurized clinical samples of milk from sick cattle collected from two dairy farms in Kansas and one in Texas, as well as an oropharyngeal swab from another dairy in Texas, have tested positive for highly pathogenic avian influenza (HPAI). Additional testing was initiated on Friday, March 22, and over the weekend because farms have also reported finding deceased wild birds on their properties. Initial testing by the National Veterinary Services Laboratories has not found changes to the virus that would make it more transmissible to humans, indicating that the current risk to the public remains low. Federal and state agencies are conducting additional testing for HPAI and viral genome sequencing to better understand the situation.
At this stage, there is no concern about the safety of the commercial milk supply or that this circumstance poses a risk to consumer health. Dairies are required to send only milk from healthy animals into processing for human consumption, and pasteurization has proven to inactivate bacteria and viruses, like influenza, in milk. Federal agencies are working with state and industry partners to encourage farmers and veterinarians to report cattle illnesses quickly to monitor potential additional cases and minimize the impact on farmers, consumers, and other animals.
The disease has caused a drop in milk production and unusual milk appearance, with some cows showing signs of fever, mastitis, or pneumonia. Production may be reduced for seven to 10 days until symptoms subside. The Texas Department of Agriculture is not predicting depopulation of dairy herds, as cattle are expected to fully recover. Symptoms are most common in older, mid-lactation cows, with no reported cases in calves, heifers, or dry cows. The state is urging all Texas dairies to adhere to strict biosecurity protocols, including limiting farm access to essential personnel, disinfecting vehicles, isolating affected animals, and destroying contaminated milk. Additionally, waterers should be cleaned and disinfected, and drinking water should be isolated from waterfowl-contaminated water sources.
