The Colorado Department of Agriculture (CDA) today reported its first avian flu outbreaks in dairy herds that are based on mandatory weekly bulk-tank milk testing, which went into effect on July 22.
The testing turned up nine more outbreaks in dairy herds, according to the CDA’s line list, which now reflects 63 herds affected since late April.Â
More than half of Colorado’s licensed dairy herds have been hit with outbreaks, many of them in Weld County, where the virus spread to a large commercial poultry farms and infected 10 livestock workers and poultry cullers.
 So far, Colorado is the only one of 13 affected states to order regular bulk tank testing.
Officials haven’t said if the cows at the farms identified through bulk tank testing had clinical signs.
As of today, the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed 179 H5N1 outbreaks in dairy herds from 13 states. Among the total are 52 from Colorado, which has the most of any state.
Governor extends emergency declaration
In a related development, Colorado Governor Jared Polis on August 2 extended an emergency declaration an extra 30 days — through September 1 — to free up resources for the avian flu response in Weld County.
Polis first announced the emergency declaration on July 5.
