Exercise, exercise

You almost certainly all ready walk your dog at least once a day, right? If not, you certainly should. Even if you are, is it really enough? The answer to this will depend on the size and the breed of your dog. A large dog can run for a mile with little trouble whereas a lapdog could be happy with a once around the field. Some breeds inherently require more exercise than others and you need to be sure that you are giving your dog sufficient exercise.

Ways of increasing it are by taking the dog out twice a day or finding a field if your garden isn't big enough, where you can throw a ball for your dog to retrieve. Most will do this with a little training. 
A larger dog will run with you if you are into jogging, or even if your on a cycle, provided it's within a safe environment. A smaller dog can get more exercise, and pleasure from simple games such as tug of war, or chasing up and down. Any such exercise is good for your dog, and for you too.

Ultimate Guide to Dog Health