I was so very lucky that all three of my pets really did let me know when. The dogs both weighed more than me, so when they couldn't walk anymore, well, it was time to do something. One just laid down and never got up again. It was still the most heart-wrenching experience to say "It's time" out loud.

Even if they don't tell you, you will know it's the right time - when their quality of life is gone, they're in pain, or will be in pain shortly. Take care of yourself, in whatever you decide.