|Boo Boo the Wonder Dog, looking ready for a new adventure|
It's something that as a dog owner you'll need to come to grips with one day and do the right thing for you and your loyal companion. It'll be one of the tougher decisions you'll have to make, but you're the only one that can make it for both of you.
My primary recommendation is to establish the ground rules for how you're going to decide to euthanize your dog well before the time comes if you have the choice. You'll want to be as objective as possible so you can look back without doubt that you did the right thing.
Make sure that you understand that the decision is yours. Your dog isn't going to tell you if it's time or not. Your dog's only goal in life has been to make you happy and be happy itself. A dog in pain may or may not show signs that tell you when is the right time. Make sure you're working with your vet and determine what an acceptable quality of life is.
Don't make the decision to put your dog to sleep because it's the convenient thing to do. I can't think of a more horrible thing, but unfortunately bringing the dog to be put to sleep or dumped at a shelter because of rising veterinary costs is unfortunately not uncommon. There are alternatives for financial help for people trying to care for their animals in this tough economy if you look.
On the other side of the fence, don't make excuses for dragging it out. No creature lives forever and you don't want to question whether you were part of torturing an animal in its last days for no better reason than keeping it around for yourself.
The best book that I've read on the topic is Is It Time to Say Goodbye? A Guide for Considering a Difficult Decision for your Pet. It's not an easy topic to address, so if you know someone who is struggling over this decision, point them to this book and let them know that you're there for them.