About that walk... the objective is not the walk. The objective is to expend a dog's excess energy whether it be a walk, a game of fetch, hunting sport, tracking, herding, agility training, etc. etc. This is the same for cats too. A bored dog/cat can be destructive as they try to find things to do on their own. Some dogs - like most adult English Bulldogs - gets wiped out with 10 minutes of fetch play. Some dogs - like a German Shorthaired Pointer - run (not walk) for 20 miles before getting wiped out. So, part of dog ownership is to be able to give the dog an activity to drain that energy balanced with it's bone/muscle/lung capacity. Angus, my English Bulldog, is so motivated that if I don't quit throwing the ball, he will not stop playing fetch until he passes out from exhaustion. Young Great Danes have to balance their exercise with their bone development, so instead of giving a young Great Dane one long walk, they do better with multiple short walks. That kind of thing.