Animals in at least two Sedgwick County cattle herds have died of anthrax, the Colorado State Veterinarian’s Office confirmed Tuesday, the first such cases in a decade.

The first case was identified on July 23, after a producer had seven cattle deaths, the state said in a news release.

A second case, from a separate herd, was identified Tuesday. The deaths are the first anthrax fatalities in Colorado among cattle herds since 2012. Two people have also been exposed and are under observation at a health facility, the state said, adding that the risk to the general public is low.

Anthrax can naturally occur in Colorado soil, the state said, and spores can lie dormant, emerging after storms, excavation or flooding. Animals are exposed to the spores when they’re grazing or consume contaminated food or water; this usually happens in the mid to late summer, the state said, and anthrax is commonly detected in a number of states every year.

The two herds are being monitored, vaccinated and are under quarantine.

“Livestock producers in northeast Colorado should monitor their herds for unexplained deaths and work with their veterinarian to ensure appropriate samples are collected and submitted to a diagnostic lab for testing,” Maggie Baldwin, the state vet, said in a statement. “Producers and veterinarians should refrain from performing field necropsies on suspected anthrax cases, due to the high risk of exposure to anthrax spores and possibility for human infection.”

Field necropsies – when dead animals are examined outside of a professional setting – can further spread anthrax, the state said.

In 2012, when there were last confirmed anthrax cases among cattle herds, more than 75 animals died in outbreaks across northeast Colorado.