PORTLAND, Ore. (KOIN) – An animal sanctuary in Washington is under quarantine after 20 big cats died amid a bird flu outbreak, the Wild Felid Advocacy Center announced.

The sanctuary, located in Shelton, Washington, announced the outbreak of Highly Pathogenic Avian Influenza (also known as bird flu) in a December 20 Facebook post, saying, “We are heartbroken to share that animal health officials have confirmed the presence of highly pathogenic avian influenza (HPAI) among over half of our wild felids as of December 2024."

The cats that died from the bird flu outbreak include a half Bengal tiger, four cougars, three lynx, and four bobcats.

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The sanctuary explained that the viral infection spreads primarily from bird-to-bird contact however, the virus can also be contracted by carnivorous animals that eat birds or other products.

According to the sanctuary, cats are particularly vulnerable to the virus, which can cause “subtle initial symptoms but progress rapidly, often resulting in death within 24 hours due to pneumonia-like conditions.”

The sanctuary said it is working with state and federal animal authorities, along with Mason County health officials, to determine the origin of the virus and help prevent further spread, as reported by The New York Times -- noting the first big cat death occurred Nov. 23 and the latest occurred Dec. 13.

According to The New York Times, wild bird droppings might have entered the cat habitats, or meat used to feed the animals could have held the virus as well -- leading the sanctuary to remove 8,000 pounds of food that was stored in a freezer to prevent further infection.

Additionally, the sanctuary announced it is under quarantine and will remain closed until further notice. While under quarantine, the sanctuary said it is equipped to handle outbreaks through various measures such as quarantining affected animals and undergoing disinfection protocols.

“This tragedy has deeply affected our team, and we are all grieving the loss of these incredible animals. Now, we turn to the community for support as we focus on the care and recovery of our surviving felids. The mounting medical costs, even at discounted rates, have placed a significant financial strain on our sanctuary," the animal center said in a Facebook post -- encouraging community members to make donations through their website.

The announcement comes after the Washington Department of Fish & Wildlife confirmed the state's first-ever bird flu case in cougars.

On Friday, the department confirmed to KOIN 6 News that two wild cougars died from HPAI in Clallam County -- near Sequim and Port Angeles.

The first cougar was found November 19, and the other was found November 28, WDFW said. One of the cougars was found dead while the other was humanely euthanized after it was found ill.

WDFW has also confirmed avian influenza in numerous wild birds in the fall, especially in the western part of the state.

“While the spread of HPAI, in particular H5N1, from birds to mammals is concerning, it is not surprising. To date, there is no indication that HPAI viruses are circulating in wild mammals. Rather, cases are directly related to mammals scavenging on infected wild birds such as waterfowl,” WDFW said.

The cases come amid bird flu outbreaks across the United States, including an outbreak reported on a commercial poultry farm in Franklin County, Washington, where the state also saw its first reported cases of humans with bird flu.

According to the Centers for Disease Control and Prevention, humans have a low risk of catching HPAI.