I know the feeling. I was pet sitting for a friend about a month ago. I let the dog like usual at night, next thing I know I hear a cat hissing and meowing like it was being strangled to death. It was just that, the dog(a hyperactive dalmation) had it in its mouth and shaking it like there was no tommorrow. It was only a stray, but man did I hate myself for not rescuing it.
I feel for you.
