DES MOINES, IOWA — The Iowa Department of Agriculture and Land Stewardship reported June 5 a positive case of highly pathogenic avian influenza (HPAI) in a dairy herd, the state’s first case involving a cow.

The US Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) confirmed the detection, which was discovered in O’Brien County, Iowa. 

With this report, 10 states have now reported HPAI in dairy herds: Iowa, South Dakota, Texas, Ohio, North Carolina, Michigan, Kansas, Idaho, New Mexico and Colorado. More than 80 dairy cases have been reported, according to data from APHIS.

“Given the spread of highly pathogenic avian influenza within dairy cattle in many other states, it is not a surprise that we would have a case, given the size of our dairy industry in Iowa,” said Iowa Secretary of Agriculture Mike Naig. “While lactating dairy cattle appear to recover with supportive care, we know this destructive virus continues to be deadly for poultry. Our team at the department has been preparing for this possibility and will soon be announcing additional response steps to protect our flocks and herds.”

The report came soon after two other outbreaks of HPAI in Iowa. On May 28, the state detected the virus in a commercial layer flock in Sioux County that affected 4.3 million birds. Less than a week later, Cherokee County reported an outbreak in a commercial turkey flock, affecting 100,000 birds.

In response, Iowa Gov. Kim Reynolds signed a disaster proclamation for Sioux County and Cherokee County. The proclamation allows state resources from Iowa Homeland Security, the Iowa Department of Agriculture and Land Stewardship and other agencies to assist with tracking and monitoring, rapid detection, containment, disposal and disinfection, while also waiving regulatory provisions related to commercial vehicles.

The Iowa Department of Agriculture and Land Stewardship said the genomic sequencing of the virus detected in Sioux County was determined by the National Veterinary Services Laboratory in Ames, Iowa, to be consistent with the variant identified in affected dairies in other states. Meanwhile, sequencing on the virus detected in Cherokee County, as well as the dairy detection in O’Brien County, are still in progress.

“Epidemiological investigations are ongoing to try to determine how the virus was introduced into the flocks and herd,” the agency said.