A dog left alone may be reacting to the absence of family members. If this is the case, you need to work with your dog to help it tolerate gradually longer absences. Your veterinarian can help you plan this behavior modification training. During summer months, if your dog digs a hole to cool itself, consider providing a cooler location for it such as an umbrella, or inside the house or basement. If your dog is housed outside, be certain it has access to some shade throughout the day and that fresh drinking water is always available.
Some dogs find hot weather comfort in their own wading pools with fresh, cool water.
Some dogs tend to roam and will dig under a fence to get out of the yard. Ideally, a fence should fit tight to the ground or even be buried a few inches underneath to prevent a dog's crawling or digging out from under it. If your dog is trying to escape, try to determine why it is leaving home. Unless you plan a responsible breeding program which includes placing puppies in good homes, neutering is recommended. A neutered dog is generally calm and tends not to wander.