It is generally recognized that bitches (females) are protective of their homes and dogs (males) protective of their owners. But those beliefs are oversimplified and require some explanation.
First of all, you must understand why dogs protect. It certainly is not because someone loves them; most dogs are loved. It certainly is not because someone feeds them; all dogs are fed. It certainly is not because they live in a certain house (which they protect); all our dogs live somewhere.
Rather, dogs protect the people they relate to and the homes in which those people live. The word "relate" here indicates that the dog thinks of himself and the person as a team, a unit in which both will be injured if one is injured. In other words, dogs are not altruistic. They do not protect out of love, but out of fear. If they believe something will harm them, they will protect themselves-and the person to whom they relate, who is part of the same unit.
This feeling of togetherness, which results in protective-ness, is best created by obedience training to a high level of performance. Some people achieve the same result because of their natural talent for making the dog their alter-ego (in a healthy sense of the word). But for most of us, a high level of obedience training is the best way. Most important: the obedience training must be achieved by the positive methods I'll outline here. A dog will not relate to, much less protect, a person who mistreats him. In fact, he may even side with the mugger!
Bitches seem to develop a high sense of premises protection at an early age, but this quality is natural to all dogs who relate to the people who live in the house. Don't expect your dog to bark at the doorbell or sounds near the house until he is at least seven months old. But if protectiveness is particularly important to you, rush the dog to the door with you whenever the doorbell rings, and say "Who's there?" in a tone that implies mistrust, wariness. Do the same whenever you hear a strange sound. When your dog begins to sense these dangers and runs to the door to listen, growl, or bark at unusual sounds, encourage him with, "Good boy," and continue saying, "Who's there?" in that scary tone.
Then once you ascertain the source of the sound and are sure it represents no danger, tell the dog. "Thank you, that's enough." And make him stop. Be sure he is under control before you open the door. A dog that barks at the door is one thing; a dog who attacks your best friend is another.
It is most important to recognize that your own attitude is the key to the dog's display of protectiveness. For instance, I live in a garden apartment in Manhattan and am understandably tense about strange noises. My Shelties bark at the drop of a pebble in the garden. As a result, the police are called and burglars are caught before they even have a chance to "case the joint." On the other hand, when I spend a weekend with friends who live on a high floor of an apartment building, I relax completely (how many burglars come in through a twentieth-floor window?) and the dogs bark only if someone rings the bell. They don't notice the sounds of people walking in the hall any more than I do, nor should they