I'm so sorry to hear of your loss....my deepest condolences.
Hearing of this makes me think of the pets I've lost in my life. It truly is one of the tougher things to have happen in your lifetime. I think dogs are the toughest pet to lose...they are at their happiest when you come home and spend a little quality time with them.
At least your last memory of Sammie will be one of him happily wagging his tail and seeing you out the door.