Bird flu kills wild cats at a sanctuary in Washington

The video discusses the impact of bird flu on various animals. A house cat in Oregon died after consuming pet food contaminated with bird flu. In Washington, the virus has killed over half the big cats at a sanctuary. Additionally, nearly 900 herds of cattle across 16 states have tested positive for bird flu, with the transmission method still unknown.

What symptoms were observed in the cats that died due to the bird flu virus?

What is still unknown regarding the transmission of the bird flu virus to animals?