Health officials are making a renewed call for vigilance against bird flu, but some experts are puzzling over why reports of new human cases have stopped.

The first major global review of bird flu in cats reveals an emerging threat of a potential human pandemic. Spring is here, birds are on the move, and a new threat is spreading alongside them: bird flu (H5N1).

Cats infected with bird flu are falling under the radar when it comes to tracking and managing the virus, and this must change rapidly, scientists warn in a new paper.