Everyone has given excellent advice. Cannot add much to it.

We did give our cat the Sub-Q fluids at the end of her life. As long as she was able to get up to greet me (she did not need to walk to me), I was going to keep her comfortable.

I have had many cat/dog loves. I think you will know when the animal tells you to let them have peace.

Makes me cry even as I type this. But the tears are full of great memories.