It is your responsibility to assure that your dog cannot escape from your property. No dog is perfect so do not expect your dog to always be able to resist the temptation of following children, visiting other dogs or chasing cats. Dogs that are isolated or confined for long periods of time become bored and restless. They may try to escape to find entertainment elsewhere. The escape act itself may be a form of entertainment.
Many dogs escape just for the fun and challenge of it.
Schedule daily exercise, play and training sessions with your dog. A good, hardy play session especially with other dogs will tire your dog and give him the exercise he needs. A happy, well-exercised dog will contentedly sleep the day away while you are not home. Make your property escape-proof. Be sure the fence is tall enough to prevent jumping or climbing.