That is a good video, except for the notable exception of the portion of the video at around 1:23 or so. That picture is an example not of the loyalty and courage of dogs, but of man's cruelty towards them. That picture, of the dog wearing a backpack, is picture of a soviet dog mine in action. The Soviet Union trained dogs to associate food with the underside of tanks, then strapped explosives to the dog's back set to explode once the dog was underneath a tank. Ironically, and the ultimate example of karma being a you-know-what, the dogs almost invariably associated food with the underside of Soviet tanks, thus paying the soviets in turn for their cruelty.