A second type of bird flu has been found in U.S. dairy cows for the first time, the U.S. Department of Agriculture (USDA) announced on Wednesday. Until recently, all dairy herd detections in the U.S.

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.