H5N1 strikes dairy herd in Michigan, large poultry farm in Colorado


The Michigan Department of Agriculture and Rural Development today announced that tests have identified H5N1 avian flu in a dairy herd in Gratiot County, the state’s first outbreak since June 7.

In other H5N1 developments, the Colorado Department of Agriculture today said the virus struck a large commercial layer farm in Weld County.

Recurrence in a Michigan hot spot

The outbreak in Gratiot County brings the number of H5N1 outbreaks in Michigan dairy herds to 26. In a statement, MDARD Director Tim Boring, PhD, said tests at the Michigan State University Veterinary Diagnostic Laboratory initially detected the event and that samples will be sent to the US Department of Agriculture (USDA) National Veterinary Services Laboratory for additional confirmation.

Gratiot County has been one of Michigan’s hot spots for both dairy herd and poultry farm outbreaks involving the virus.

The number of dairy herd H5N1 outbreaks confirmed by the USDA Animal and Plant Health Inspection Service (APHIS) stands at 140 from 12 states, of which 25 are from Michigan.

Colorado outbreak prompts emergency declaration

Colorado, another state hit hard by H5N1 in dairy herds, has recently reported a few outbreaks in backyard birds, but has now reported its second-largest outbreak in commercial poultry since the virus emerged in US birds in 2022. The facility is a layer farm housing more than 1.7 million birds, according to a Colorado media report.

Weld County, where the farm is located, has also been heavily affected by H5N1 outbreaks in dairy herds.

On July 5, Colorado Governor Jared Polis declared a disaster emergency due to the poultry outbreak, which ensures that the state can provide support and resources for the agriculture industry, according to an announcement yesterday.