Dozens of cats across the U.S. have tested positive for avian flu, federal officials say. The west coast has been hit especially hard.

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.

The Wild Felid Advocacy Center of Washington announced it is under quarantine amid a devastating bird flu outbreak that has killed 20 big cats.