What a sad but wonderful friendship over the years you had with Doc.
I know that God put dogs on the earth to be our best friends as I have had many myself. The German Shepards or pure bred Shepard mutts (and even my wife`s little hot dog of a mutt) that I have had to watch go on to the beaches, mountains and fields in the sky brings tears to my eye`s even now.
I feel your pain and I pray that you know Doc is to this day and for every day in the future with you in heart and spirit.
God Bless
Marc