All dogs need exercise and attention, some breeds more than others.
Owning a dog is a daily commitment. It gets you out of bed early, forces you to walk around your neighbourhood on even the rainiest of days, requires constant feeding, love, and attention. And they reward us for it: dogs think we humans are gods. We're their favourite thing in the world (except maybe food), despite the fact they don't even know our names.
Every day when I walk my dog, I see the same people walking their dogs, too. I also see dogs caged up in people's yards that never seem to get walked - as if their owners think the ability to run around a small square of grass is sufficient exercise
Most dogs need a walk at least twice a day, for a total of 30 to 60 minutes. A good sign your dog is well-exercised is when he or she has slowed in pace by the time you're finishing your walk. If you have a hunting, herding, or working breed (think your retrievers, Labradors, hounds, collies, spaniels, shepherds, etc.) they not only need that 30 to 60 minutes of walking but also another one to two hours of other activity.
Chances are your dog's not getting enough exercise, right?