Dogs are pack animals. They have a highly developed social system, with a definite hierarchy within the pack. There is a dominant or "alpha" dog, a "beta" dog, and so on, and at the bottom of the social ladder, an "omega" dog. The alpha dog may be male or female. These social roles are very important to the pack.
Members of your family are considered members of your dogs pack. They will look to you as a leader of the pack. If you don't ask this way, your dog will look to fill that position.
Dogs within the pack usually interact in a predictable way and maintain the social order of the pack. Much of their behavior is aimed at maintaining their social status, or sometimes at improving it. When the alpha dog dies or becomes old or is otherwise unable to continue in his position, there is competition for the top position. Likewise, when a new member is introduced to the pack, there is a rearrangement of social status and some challenge to positions.
The older the pact, the more established the social status. The more established the social status, the fewer conflicts there are within the pack. The alpha dog will often break up conflicts when they do occur.
The alpha dog will communicate his or her dominance to other dogs in the pack. Displays of dominance include placing a paw on other dogs, standing over other dogs, making eye contact, circling and sniffing other dogs, and urine marking.
Showing submission to the alpha dog is another important part of communication within the pack. A dog will lie on his back, spread his legs, and expose his belly to the alpha dog. At other times, the dog will simply lower his head. He is acknowledging the alpha dog's dominance. The alpha dog usually responds with signs of friendliness and tolerance.
You may notice your dog behaving this way toward you. He may be acknowledging your dominance at times (you definitely want to be the "alpha dog" in your house). At other times, he may simply be asking for a belly rub!
Puppies begin learning about ranking and social order from the age of about four weeks. They learn about this from their mother and from their litter mates. It is important that puppies are not separated from their mother and litter mates too soon, or they will not learn this valuable lesson. Even if they will not be living with other dogs, they need to learn about social order because they will view the people they live with as members of their "pack".
Changing Dog Pack Behavior
If your dog sees you accept another person or animal, then your dog will see that you are still the leader and will exhibit the appropriate dog pack behavior. If they don't see you interact with other people then they will step into the void. For example, your dog may go after the mailman if when you weren't present their barking caused the mailman to leave. Over time the uniform becomes a symbol of an invader of your dog's territory. To change this behavior your dog has to see you as the leader of the pack accepting people in uniform.
If the dog pack behavior is acting as if he or she is the leader of the pack over you, then you need to establish a clear set of rules for your dog so that he sees who is boss.
Send a Signal to Your Dog: Do not play with your dog or encourage bad behavior. Keep your dog off your bed and off furniture. Those places are reserved for human leaders of the pack.
Provide Clear Structure: Train your dog to follow simple commands such as sit and stay. Any time your dog is acting out of line, invoke the commands to control the situation. Reward your dog with treats for conforming behavior.
You can enforce this structure when walking your dog. According to the ASPCA you should change walking directions if your dog is moving too far ahead. If your dog blocks you with his body continue to lean forward. Insist that your dog sits on every corner to exert control. Vary the speed of walking so that your dog is forced to follow your lead.
Following this type of approach should correct the behavior is approximately 30 days.
Aggressive Dog Behavior vs. Dog Pack Behavior
If you unable to correct the dog pack behavior and there are other signs such as snarling or baring the teeth, then your dog could be exhibiting aggressive dog behavior. Your veterinarian will review a set of criteria for determining if the aggressive behavior can be corrected, controlled with medications or dangerous to your family.
If the behaviors are provoked or triggered by circumstances in the home such as the entrance of strangers or anxiety, then medications or behavioral modification could help. If the aggression just appears unexpectedly or uncontrolled then your dog should be carefully evaluated, particularly if you perceive a threat to your family.