I don't believe animals should be put to sleep unless they are beyond help. However, this poor angel of a cat has no quality of life left.
It's not as if she was born this way and is adapted to living like this, she has spent her entire life as a 'normal' cat doing cat-like things. I look over at my cat right now and she's cleaning herself and chasing some random speck of dust. Those are the things that cats are naturally driven to do. This poor kitty still has those urges, she just has to suffer and not be able to do them.
It's not a matter of her sitting around thinking about her old life, it's a matter of her not being able to act on any of her natural instincts.
I wish they had fake limbs for animals. That poor baby.
