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.

Northwest Naturals is recalling a line of its pet food after authorities linked the death of a cat to a batch of food contaminated with bird flu.

The animals - including a Bengal tiger, cougars and bobcats - have died of the virus over the past several weeks.

The Oregon Health Authority and local officials are monitoring household members who had contact with the cat for flu symptoms.

Northwest Naturals issued a voluntary recall for a batch of pet food after a cat died of bird flu in Oregon, officials said. Testing done by the U.S. Department of Agriculture's National Veterinary Services Laboratories and the Oregon Veterinary Diagnostic Laboratory confirmed an indoor cat in Oregon's Washington County contracted bird flu and died after eating the pet food.