Bird Flu Spreads to Dairy Cows

A highly fatal form of avian influenza, or bird flu, has been confirmed in U.S. cattle in Texas and Kansas, the Department of Agriculture announced on Monday.

It is the first time that cows infected with the virus have been identified.

The cows appear to have been infected by wild birds, and dead birds were reported on some farms, the agency said. The results were announced after multiple federal and state agencies began investigating reports of sick cows in Texas, Kansas and New Mexico.

In several cases, the virus was detected in unpasteurized samples of milk collected from sick cows. Because pasteurization kills viruses, officials emphasized that there was little risk to the nation’s milk supply.

“At this stage, there is no concern about the safety of the commercial milk supply or that this circumstance poses a risk to consumer health,” the agency said in a statement.

Outside experts agreed. “It has only been found in milk that is grossly abnormal,” said Dr. Jim Lowe, a veterinarian and influenza researcher at the College of Veterinary Medicine at the University of Illinois at Urbana-Champaign.

In those cases, the milk was described as thick and syrupy, he said, and was discarded. The agency said that dairies are required to divert or destroy milk from sick animals.