I'm sitting here googling 'when to put your cat to sleep?' My poor Annie. She still seems perky enough. She eats cheerfully, although not huge amounts. She is up and around but spends most of her time in her little heated pod. She cries when I pick her up, but she has ALWAYS cried when I pick her up. She's skinnier than ever despite her eating. I just don't know.
The other cats seem to be relatively respectful of her which also means they know she's not herself.
Of course, the other cats also don't want her gone as their bonanza of leftover canned food and treats buffet will be over, so that may be their end game.
It's so hard to know. What a surprise. It's always hard to know the tough things.