In "To Build a Fire" by Jack London, what value assumptions about animals underlie the man's interactions with the dog? How does the story's plot...

There is the anthropocentric assumption that humans are more intelligent than all other animals, including dogs. Therefore, the reader would perhaps assume that the man knows best and that the dog is merely operating under its own simplistic instincts. The plot of this story proves this notion to be incorrect. The man is too proud. He recognizes this too late. The old-timer on Sulphur Creek had told him to take a companion with him but...

There is the anthropocentric assumption that humans are more intelligent than all other animals, including dogs. Therefore, the reader would perhaps assume that the man knows best and that the dog is merely operating under its own simplistic instincts. The plot of this story proves this notion to be incorrect. The man is too proud. He recognizes this too late. The old-timer on Sulphur Creek had told him to take a companion with him but the man refused. His pride overrides his supposed higher intelligence (relative to other animals) and he uses this pride to override his instinct as well. Meanwhile, the dog's instinct is correct: 

The animal was depressed by the tremendous cold. It knew that it was no time for traveling. Its instinct told it a truer tale than was told to the man by the man's judgment. 

When the man decides that his only chance for survival is to cut the dog open and warm his hands in the carcass, the story shows that the man has become the more savage creature. To be sure, he is out of options and is now acting on instinct and reason in order to survive. But note that, after the man has died, the dog doesn't feed on him or harm him in any way. The dog simply heads toward the camp. So, the assumption that this wolf-dog is more wild and therefore more savage than a man is overturned as well.