Could be *really* creepy is it's handled right! I can see this being something that's really dark, subtle, understated. Give us really unsettling visuals -- don't go all concept on us -- canine facial images which belie some kind of bloodhtirsty, malevolent intent. If they could totally exploit some subconscious fear regarding man's best friend surreptitiously turning against him -- by eating him, no less -- I think they'd have a very effective film. Just do not go off on any *action* tangent. Make it a truly unsettling slow-bunr, and I think they'd have something quite interesting.