State confirms bird flu in Weld County dairy

Colorado agriculture officials confirmed Friday that the state’s first bird flu case in dairy cattle since 2024 has been detected in Weld County. The finding came after a routine test of a bulk milk tank returned a positive result for the virus. State leaders said the case marks the first confirmed instance of highly pathogenic avian influenza in local dairy cattle since August 2024.

The initial screening produced a presumptive positive result. Subsequent testing by a U.S. Department of Agriculture lab confirmed the presence of the virus on Oct. 24. State officials released the information Friday in a formal news release. The dairy in question has not been named publicly.

The farm is now under a quarantine order. This restriction limits the movement of milk cows and enforces strict biosecurity protocols across the property. Officials require two consecutive negative tests, taken at least one week apart, to lift the quarantine. State agriculture officials are coordinating with the Colorado Department of Public Health and Environment to protect workers on site.

The current situation follows a larger outbreak that began in April 2024. That previous wave affected 64 Colorado dairies. In response, state officials launched the country’s first mandatory bulk milk tank testing program for commercial dairies. That testing program successfully cleared the virus from all affected herds.

Colorado Department of Agriculture officials stated that the general public remains at low risk. They noted that pasteurization kills viruses, keeping pasteurized milk safe for consumption. The primary risk lies with individuals who come into direct contact with infected birds or other animals.