A dog fence acts as a physical barrier that prevents the dog from going to the other side, but it is different from a normal fence in a number of ways. It prevents the dog from jumping over the barrier; it equally prevents the dog from digging under it. A simple fence will keep the dog from going to the other side of the fence but once it spots another dog, it may get excited and jump over the fence. Fences for dogs have a number of designs that prevent dogs from doing this.