Bird Flu Outbreak Spreads to Dairy Cows Across Six U.S. States

Federal and state officials investigate as evidence suggests cow-to-cow transmission, while assuring the public that the milk supply remains safe.

Bird flu, officially known as HPAI, has spread to dairy cows in six states, including Idaho, Michigan, New Mexico, and Ohio, with evidence suggesting possible cow-to-cow transmission.
The virus strain in Michigan is similar to those found in Texas and Kansas, likely introduced by wild birds, with no current changes making it more transmissible to humans.
Federal and state officials are investigating the outbreak, which has caused decreased milk production and appetite among affected cows, though most recover after isolation.
The commercial milk supply remains safe for consumption as infected or exposed milk is diverted or destroyed, and pasteurization inactivates the virus.
This is the first time dairy cows in the U.S. have been sickened by bird flu, raising concerns about the virus spreading to other species, including humans.