We believe that any human or even a Buddha, a Bodhisattva or any other high being can be re-incarnated as a dog to help these beings. You cannot see this from the outside. Therefore we treat all creatures with much respect.
There are many Lamas in high positions who were and still are dog lovers. I can show you many pictures of Lamas with Tibetan Spaniels. Often the dogs sit next to the Lamas or on their laps. As the Lamas often sit still for a long time and meditate, the dogs feel very comfortable on their laps.
These dogs often behave very much like human beings. I had for example a Lhasa Apso which turned almost 18 years old. This dog gagged for cats, other dogs and puppies. Once when he had to do his business and could not go outside, he got hold of a piece of paper and went on the paper. When babies were visiting and they started to cry, he would go to them, console them and try to comfort them. He clearly showed traits of compassion and altruistic behaviour.