That's so sad but touching. Dogs are so loyal and many people don't really think about how sad dogs could really be, especially since they are so loyal. If you are bound to something so strongly by emotion and suddenly that's gone, you would be really sad. I can imagine how heartbroken this dog could be over this death.
That's so heartbreaking.
I have three dogs, and it isn't hard to imagine my Golden watching over any of my other two. looking at all the animal stories makes me think about how much wiser they are than we think. Bless those dogs.