When it comes to dogs, there is no concept more widely embraced and debated than the concept of dominance. It is a concept cloaked in a veil of myth, legend and science.
Understanding dominance
Dominance is an extremely complicated social dynamic. For general purposes, however, it is useful to think of dominance as leadership. The top member of a social hierarchy is commonly referred to as the alpha. The alpha is the leader who has ultimate responsibility for the pack. Every social animal from pigs to humans has hierarchies, and "dominance." The reason for social hierarchies in the wild is clear. Hierarchies keep the peace. In the wild, there are limited resources. A species fighting among themselves over resources would not thrive.
Since hierarchies evolved to keep the peace in a pack or herd, it is interesting that people often attribute aggressiveness or other problems to alpha behavior. A true alpha dog is confident enough in his strength and leadership that he very rarely feels the need to prove it. In my experience, it's the middle ranking dogs that are most likely to exhibit aggression. The top and bottom rankers have little call for it.
It is not only aggression that people often incorrectly attribute to dominance. I've heard clients cite dominance for just about every behavior from herding breeds nipping to submissive urination. There are many day-to-day behaviors that are not driven by a dog's desire to dominate. Most behaviors can be attributed to instincts or tactics the dog has learned that work at getting what he wants. However, just because your dog isn't lying awake at night devising plans to become the alpha doesn't mean your leadership isn't important.
Establishing Leadership
In the "pack" created by you and your dog, your leadership (or alpha status, if you prefer) is critical in deciding the behavior, mental state and general wellbeing of your dog. Being a consistent leader will make your dog feel secure and curb many behavior problems. The key is to be a leader that your dog loves and respects.
Leadership is a way of life, not a series of confrontations that the dog must lose. Every interaction with your dog is an opportunity to establish leadership. To determine if you are the leader, ask yourself: "Who is influencing whose behavior?" Do you eat quickly in your dog's presence? Do you throw the ball so he will quit barking? If so, your dog is influencing you. Your dog is making important decisions for himself and will be less accepting of your direction in other situations.