German Shepherds can be highly effective dogs when you are looking to protect your property. However, they need to be properly trained for the sake of both safety and effectiveness. The following are six important things a German Shepherd must be aware of in order to function effectively as a guard dog: What the exact boundaries of your property are Dogs are very territorial animals. You need to impress upon your guard dog the limits of your property so that your dog is not attempting to intrude on your neighbors' land.