I believe we owe it to our critters to help them cross the bridge when they no longer have quality of life. I know some people think I'm daft, but I'll ask my guys if they are ready to go. I count myself very lucky that I have a small animal I trust to give me an honest answer if I ask her opinion.
Gawd, I am getting choked up just typing this.
I've said for years that we should be able to do something similar for humans. I don't want anyone else making the decision for me, but would like the option of being able to pull the plug when my body gives up.