One of the theories surrounding the relationship between man and dogs is the fact that they both were able to "run/trot" all day long while hunting, something that most predators can't do. In theory this led them to be good hunting partners using the human brain and eyesight and the dogs sense of smell to track and capture prey.
They present some of the physiological and behavioral characteristics of dogs in a somewhat different light. In fact, the authors dispute the usual "dog-as-a-tame-wolf" concept in some respect.
If you're interested in dogs, as I am, I recommend it.