Avian Influenza Detected in US Dairy Cattle and Cats, Raising Food System Concerns

In March 2024, barn cats at dairy farms in the Texas panhandle began exhibiting neurological symptoms, including circling, listlessness, loss of balance, staggering, seizures, and paralysis, often leading to death within days. At one North Texas dairy, two dozen cats developed these symptoms, with over half succumbing to the illness.

Dr. Barb Petersen, a veterinarian in Amarillo, investigating an unrelated illness among dairy cattle, noted that cows were experiencing fever, decreased milk production, and weight loss. The milk produced was thick and yellow. Initial tests on cow samples were negative for known cattle diseases. Petersen observed a potential link between the cat and cow illnesses. Subsequent examination of dead barn cats at an Iowa State University lab revealed that they had been infected with highly pathogenic avian influenza A (H5N1).

H5N1 Transmission and Discovery

The dairy cows were found to be suffering from H5N1, and the barn cats had contracted the virus after consuming raw milk from the infected cows. H5N1, which originated in Asia and reached the United States via migratory birds, had caused significant culling at US poultry farms since 2022. While cats were previously known to be vulnerable to bird flu, primarily through eating infected birds, this discovery indicated that cows could also be infected, with the virus propagating in their udders and spreading through their milk.

Official Response and Industry Stance

Following the discovery of H5N1 in Texas dairy cattle in 2024, no mandatory testing of all cows, strict quarantines for affected dairies, mandatory milk contamination testing, or widespread testing of dairy workers occurred. The United States Department of Agriculture (USDA) oversees livestock health, while the Food and Drug Administration (FDA) lacks authority for livestock disease testing, and the Centers for Disease Control and Prevention (CDC) requires farm owner permission for animal or worker testing.

Texas agriculture commissioner, Sid Miller, publicly stated that H5N1 posed