We're talking about domesticated dogs, from Chihuauah to Malamutes - all genetically-modifed versions of the Wolf, designed to serve or entertain humans in some ways.
The domestic dog appears to be a neotonal wolf.
They are certainly trainable and well-adapted to interacting with humans, but not as clever as many other mammals. (I hear some reader thinking "But my dog is different. Yeah, right.").
How Stupid Are Dogs, Really?
Why do humans anthropomorphise animals? I am a dog guy, and know how easy it can be to view a dog as a pal. They sure can be great companions if well-trained, with none of the demands of human relationships.
I guess I am talking about pets, not pure working dogs. Are they pretend people?