re: Old dog. At what point you say good bye?

I had to put mine down last December. We made the decision because you could tell she was in alot of pain constantly and there wasnt anything we could do for her. She quit eating pretty much. Could hardly walk. Tripped trying to step over a threshold and would then just lay there looking embaressed.

In short, you will know. When there is no longer any quality of life is when its time IMO