Sorry to hear about you loss man. Put my rottie down a few months ago also. Worse feeling in the world knowing that I wouldn't see him again. The last night he was layign down knowing what was to come. He layed down for about 3-4 hours and when animal control came he got up.
And walked and jumped into the truck. Was given his free ride to the vet. We have preserved him here on the mantle. Was claimed "Gentle Giant". Miss ya Mufasa. Our dogs are both up there smiling down on us there good dog/bonny owners. Keep your chin up man. Treasure