NEW YORK, Dec. 25 (Xinhua) -- Twenty big cats, including a half-Bengal tiger and four cougars, died between late November and mid-December at a sanctuary in the U.S. state of Washington after becoming infected with bird flu, according to the facility's director.
"We've never had anything like it; they usually die basically of old age," said Mark Mathews, the founder and director of the Wild Felid Advocacy Center in Shelton, Washington. "Not something like this, it's a pretty wicked virus."
Three other cats had recovered from the virus, and one remained in critical condition on Tuesday, he said.
The sanctuary said in a statement on Friday that the facility was under quarantine and would be closed until further notice while the habitats were sanitized.
"The virus began to present itself in November within the cougar population, with several cats developing pneumonialike symptoms. Within days, other species began to show signs of illness," reported The New York Times on the deaths on Tuesday.