As you already know, and if you do not, you have the wikipedia (http://en.wikipedia.org/wiki/Dog), in real life the dog is a subspecies of the gray wolf.

It does not happen the same on LEGO world, where the dog is a subspecies that evolved from the reindog (in Spanish, perreno). Do you doubt it? These photos are the proof...

They are Perruno, at the right, and Perruna, at the left. They are so domesticated that if you tell them to seat, they do!