TERRITORIAL AGGRESSION:  Many dogs were bred to have guarding instincts, including many of the working breeds like German Shepherds, Doberman, or Rottweiler.  Most dogs have a natural instinct to alert or guard what they perceive as their territory.  This can manifest in a dog that barks when strangers approach the yard or won’t let visitors come into the house.  Look into a breed’s history and you may find territorial aggression was a selected trait used for guarding property or livestock flocks and herds.

SIGNS:  Patrolling the yard, house, windows, or yard.  Barking or growling when people or other dogs are seen approaching.  A dog that takes regular walks around the neighborhood or marks its territory may consider the whole block part of its territory.

Territorial aggression is often made worse because the dog learns that his barking causes the threat to go away.  When the mail carrier comes, the dog barks, and so the person leaves.  The dog does not know that they were going to leave anyway- they think it was their barking that warded them off.  Similarly, if the dog growls and someone backs away, the dog learns it works.  Being in small or confined areas makes territorial aggression worse, such as a dog on a short chain in the yard, or a dog barking in the car.

TREATMENT:  This can be managed through training, obedience, teaching alternate behaviors, and leadership.  Prevention is important, as well as re-directing behavior.  For example, when your dog barks at the fence, you immediately have him come when called.  When the doorbell rings, you have him “place” on a dog bed quietly.