In world 1st, dairy cows in Texas and Kansas test positive for H5N1 bird flu

Dairy cows on farms in Texas and Kansas have tested positive for bird flu in the first known cases in cows in the U.S., and likely the world. Cows in New Mexico are also thought to have been infected, but they have not yet been tested.

Three weeks ago, the cows became sick with a cold-like illness, The Associated Press reported. The animals were producing less milk than usual, their appetites decreased and they appeared lethargic. 

Unpasteurized milk samples and throat and nose swabs showed that the cows were infected with the H5N1 strain of highly pathogenic avian influenza, the Texas Animal Health Commission announced Tuesday (March 26). This strain is known to cause outbreaks in wild and domesticated birds and to occasionally infect people. 

The announcement comes a week after the first U.S. cases of bird flu in goats (Capra hircus) were reported. The goats were sharing a pasture and water source with ducks and chickens that were infected with bird flu on a backyard farm in Stevens County, Minnesota, according to a report by the World Organisation for Animal Health.

The spread of bird flu to goats "highlights the possibility of the virus infecting other Animals on farms with multiple species," Brian Hoefs, the Minnesota state veterinarian and executive director of the Minnesota Board of Animal Health, said in a statement released March 20.

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Based on the new results from Texas, officials think the dairy cows were likely infected by wild birds. The tests did not detect any changes to the bird flu virus that would make it more transmissible to humans, the AP reported.