The concerning bird flu outbreak that has spread to four humans so far as it expands quickly in the U.S. has jumped to dozens ...

Zoonotic transmission of avian influenza in the U.S. prompts worry as virus reaches cats and dogs in multiple states. A highly infectious type of avian influenza, commonly known as bird flu, has ...

Bird flu is continuing to spread in animals across the United States more than a year after ... This is believed to be the first instance of mammal to human spread of the H5N1 strain.

The bird flu outbreak has expanded to 31 states and jumped to dozens of species, including nine mammals ... The H5N1 virus could be spread through cats' saliva, feces or other body fluids.

Soon, there were more sick cattle in neighboring states ... Russo said. Bird flu has spread to over 1,000 dairy herds across the country. It has also jumped to dozens of other mammals — a ...

Health officials continue to monitor the spread of bird flu in Washington state ... keep the virus from jumping from birds to mammals. That's why state agencies and health researchers like ...

For now, bird flu doesn't easily infect humans and doesn't spread ... mammals it infects," Adalja said, "the more chances it has to adapt to mammals." More than 166 million birds across all 50 ...

N.Y. State officials worry that federal actions will harm efforts to stem the spread of bird flu. (Michael M. Santiago | Getty Images) As bird flu cases inundate more poultry and dairy farms ...