If you work with dog owners or cruise the dog behavior groups on Facebook you will often see dogs that are labeled 'dominant.' I hear this most often in client homes where they have multiple dogs and have categorized one as the dominant or "alpha" dog because of
his or her interactions with the other dogs.
He/she is often described as the dog who is stealing all the toys, pushing the others out of the way at the doorways, hoarding all of the chew bones or fighting over them, seeking – if not demanding – the humans' attention away from the other dogs, guarding the food or water bowls, playing too roughly and 'enthusiastically' with the other dogs, or keeping the other dogs off of the comfortable resting areas so they can have them as their own. It appears to be seen even more predominantly within a household where the dogs are of similar age, especially siblings.
However, if you take the same dogs out of the comfort of their home or familiar territory, or even away from their familiar play mates, you may see a very different dog.