This is Rusty. He's 17. He's blind, and deaf, and suffering from doggy dementia. Recently he's been whining a lot at the back door, and barking for no reason. The thought of putting him down hurts so much, but he's definitely suffering and we need to put him out of pain. When I first met my (now) wife 8 years ago, he refused to talk to, or even acknowledge me. It took over a year for him to accept me. How do you know when It's time to say goodbye?