I'm so very sorry for your loss. We (my girlfriend and I) recently had to put down her little cocker beagle mix that was over 15 years old and was a truly awesome dog. It was a difficult decision for us but the cancer took over his internal organs and he started refusing to eat so it was time. It still hurts bad.
Losing one to a freak accident like you did must be about as hard as it can be. My thoughts and prayers go out to your buddy, your family, and you.