re: People that run with their dog....

You need to start slowly just like you would a person. Start with a mile for a few times, then two, etc. I bike ride with my dogs and some can go 3 miles, while others only a mile. Of course, the temp matters to them as much as to you. There is a noticeable decline in their ability/desire when it gets hot. We never go in the summer unless it's very early AM.