Another spillover of the H5N1 bird flu virus from wild birds to dairy cattle appears to have occurred, this time in Arizona.

A sample of milk from a herd of dairy cows in Maricopa County has tested positive for H5N1 avian influenza, or bird flu, according to the Arizona Department of Agriculture.

Milk from every dairy in Arizona has been tested for avian flu at least once since January, but this week was the first time a test turned up positive.

Dairy cows in Nevada have been infected with a new strain of bird flu virus different from the one circulating in other herds ...

Dairy cattle in Nevada have been infected with a new type of bird flu that's different from the version that has spread in ...

Bird flu was recently detected in milk produced by an Arizona dairy herd for the first time, officials announced Friday.

Dairy cows in Nevada have been infected with a new strain of bird flu virus different from ... an evolutionary biologist at the University of Arizona, said the initial hope was that a rare ...

A variant of H5N1 bird flu that has circulated widely in wild ... an evolutionary biologist at the University of Arizona. It's not yet clear just how long the virus has been circulating in cattle ...

Bird flu is forcing farmers in Arizona and beyond to euthanize millions of laying hens and driving up egg prices. Experts say ...