Bird flu has been on the rise in Washington state and one sanctuary was hit hard: 20 big cats – more than half of the facility’s population – died over the course of weeks.

A wildlife sanctuary in Washington state is under quarantine after 20 big cats died due to H5N1 bird flu infections.

The ongoing spread of bird flu in the United States has alarmed experts -- not just because of human cases causing severe illness, but also due to troubling new instances of infections in cats.