Bird flu has been found in dairy farms in the Mountain West region but federal officials tracking the virus say it has recently spread to cattle. That has animal health inspectors concerned, though the virus — also known as the H5N1 virus — still isn’t a concern for people.

Poultry flocks across the country have already been affected by bird flu, including those in Colorado, Montana, New Mexico and Wyoming in recent weeks. The virus has spread to cattle in Idaho and Arizona, and a case of infection in 20 non-poultry birds was reported in Nevada during February, according to the Centers for Disease Control and Prevention (CDC).

The virus is extremely deadly in poultry and can wipe out entire flocks within days. But cows are better able to recover, according to the CDC. Brian Labus, associate professor with the School of Public Health at the University of Nevada, Las Vegas said human infections are concerning, but rare.

“The cases that we’ve seen so far have been people working with sick chickens or working with infected cattle and have large occupational exposures,” he said. “So far we have seen 70 cases in the United States and one person has died. But we haven’t seen it spread person to person.”

Last spring, a federal order was issued requiring testing in cattle before they are transported. Officials say that effort has prevented more spread of the virus. The CDC is using its flu surveillance systems to monitor for H5 bird flu activity in people.

Labus said processes such as milk pasteurization and proper cooking prevent the virus from spreading in beef and poultry products.

This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio (KNPR) in Las Vegas, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.