From:I Love Dogs.com
“In most ways, a guard dog is like any other dog. He needs the same care and attention and deserves to be part of a loving family. If all you want is protection and not a new addition to your family, you’re much better off investing in an alarm system. A professional security system will be cheaper in the long run (no medical bills, food, training, etc.) and you won’t have to deal with a potentially dangerous animal.”
“Do a lot of research on the different breeds of guard dogs before you rush out and buy one. If you do decide to get a real guard dog, you have to be prepared to invest an extensive amount of time and money in professional training. The goal is to end up with a dog that will aggressively protect your home and family while remaining a loving and sociable pet.
Guarding breeds need to be exposed to all sorts of people and animals from the time they are very young so that they can learn to behave appropriately around non-threatening strangers.Since most guarding breeds are naturally aggressive and dominant, they need to learn that you are the boss through your gestures, mannerisms and voice commands.
If you appear weak to one of the guarding breeds (especially the male of any breed), he will not see you as an authoritarian figure and will most likely ignore your commands. There can be only one “alpha male” in any group and if your dog will fill that role if you do not.
If you choose a dog breed that has been bred to guard flocks of sheep or cattle herds, you’ll need to have a large yard area that is securely fenced in – your dog’s territory needs to be clearly defined or else his perceived territory may expand into the neighbor’s yard or the park across the street. With this type of dog, also be prepared to be “herded” along with your other pets and children. Remember, your dog was bred to guard a flock and part of that includes keeping members of the flock in a place where they can be easily watched and protected. If your dog is properly trained, then this behavior will manifest itself as a minor personality quirk.
If you are going to own a guard dog, you have to realize that you can’t turn his aggressive qualities on and off to suit your mood. You can learn to control these qualities, however, through firm and consistent training techniques.”