Until last week, all bird flu in dairy herds had been identified as the B3.13 variant, which was believed to have come from wild birds in late 2023 or early 2024. The USDA confirmed the virus's existence in the Nevada dairy cattle through milk sampling, the agency said.

Bird flu has been detected in Arizona dairy cattle milk, and a dairy farm has been placed under quarantine as a precaution, according to officials.

Two cats that belonged to Michigan dairy workers exposed to bird flu died after being infected with the virus. But it's not clear how the animals got sick or whether they spread the virus to people.