Colorado agriculture officials have confirmed the state’s first bird flu case in dairy cattle since 2024 in Weld County, state leaders said Friday.

A routine test of a bulk milk tank came back positive for the virus, officials said.

More tests from a U.S. Department of Agriculture lab confirmed the presence of highly pathogenic avian influenza on Oct. 24 after the first routine test came back presumptive positive, state officials said in a news release.

The news release did not name the dairy where the avian flu case was confirmed but said the dairy is under a quarantine order, which restricts the movement of milk cows and requires “strict biosecurity protocols” across the farm along with two consecutive negative tests at least a week apart.

“People most at risk for avian flu are those who come directly into contact with infected birds or other animals,” Colorado Department of Agriculture officials said Friday. “The risk to the general public remains low, and pasteurized milk continues to be safe, because pasteurization kills viruses.”

State agriculture officials are working closely with the Colorado Department of Public Health and Environment and local agencies to protect workers at the dairy, according to the news release.

This is the first confirmed case of highly pathogenic avian influenza in the state’s dairy cattle since August 2024.

That outbreak started in April 2024 and affected 64 dairies in Colorado, leading state officials to institute the country’s first mandatory bulk milk tank testing program for commercial dairies.

The testing program cleared the virus from all affected herds, state officials said