Brandy/Chewbacca the possible hellhound is far more normal than some of Koontz's golden retrievers. One that springs to mind is Nickie from The Darkest Evening of the Year. Nickie is not only omnipotent, omniscient, seemingly telepathic and recognized by all other dogs as a superior being, but she is also able to heal the disabled and the blind, and raise the dead.

I'm NOT kidding. She can heal and resurrect, and she DOES.

And the fact that Nickie's possessed by an angel who happens to be the heroine's dead daughter really doesn't improve matters. She is, for all intents and purposes, a holy vessel filled with divine power who has been chosen by God to save humans and dogs alike. (Well, not all humans. Psychopaths trying to hurt the heroine need not apply.)