A writer who has lost his way hits a small dog one night while drunk driving. After taking the dog home and nursing him back to life (a dog called Lucky, by the way) the writer begins to hear voices and his writing improves. But what is the hidden cost? In many ways, the writing of this movie is by far its best strength, but also its weakness. The first ten or twenty minutes have some of the best writing I've ever seen in a horror film -- the monologue is crisp, well-thought out and transcends the simplicity and one-dimensionalness usually found in horror characters. The sad thing is, though, that while the writer is really good at this... they seem to lack the ability to move beyond this. The film never stops being self-reflective to move on to a real plot-driven film.
Now, I'm not saying the plot is bad. A speaking dog telling a man how to write and then trying to run his life is a good story, especially when it leads to murder. But the plot doesn't evolve -- it's still in the same place throughout much of the film (and it doesn't help the action never leaves the man's living room).
The dog's voice was annoying to me, and we could have used less of this (again, it tends to become repetitious after a while with no progress). But when your story revolves around the dog, I guess you're only given so many options.
Another strength was the grotesque and violent (yet, in some ways comedic) sex scenes. The average viewer would probably be appalled by the violence and the man's cold callousness. And yes, there's necrophilia. But I think this is something many horror fans will appreciate -- I saw the film with two women, which was odd, but still found the scenes as appropriate as I did disturbing.
Overall, the film is okay and in fact quite decent if you look beyond the dragging in the second half. As I've said, the writing is excellent and the acting in all cases is also great (everyone was perfectly in character and had that morbid humor I think was necessary). You could do worse than this, and if you're looking for evil dog movies, this beats the pants off stupidity like Wes Craven's "The Breed".