So the puppies noses hit the belly of the mother, and individuals are subordinate to Express their loyalty to the dominant. Pat, so must be dog is especially nice, as is a demonstration of our “inferiority”.
However, because the dog knows that his master is the leader of the “pack”, he may this gesture only be perceived as a signal of the ability of courage for individuals of lower rank. Dogs, dominant in the pack, from time to time use a light blow, this gesture of submission, in order to increase the “self-esteem” of subordinates. So the animal probably perceives our Pat.
Long and soft coat of some dogs and asks to stroke her like a cat. However, a dog that does not produce the same impression. The biggest thing we can assume is the fact that stroking recalls her first days of life when mother licked his huge tongue puppy.