How does the author use the dog to increase your sense of danger?

The dog is a "big native husky, the proper wolf dog, grey-coated and without any visible or temperamental difference from its brother, the wild wolf..." The man is a "newcomer". Basically this means that we can trust the dog's instinct more than the man's judgment. This fact is established early in the story. From then on, the dog lags behind. He is hesitant to carry on despite his fear of the man's retribution. The dog is calmed by the campfire and frightened by the trail. As the reader senses the urgency in the dog's mannerisms, the danger also increases.