I only saw part of the movie. It looked like it was probably made in the late 80's? It had to do with a family traveling in their RV with their dog. There was some kind of curse or witchcraft going on. Any there is one scene that really sticks out in my mind. The family leaves the RV and when they come back their dog is hanging dead by a noose out the RV's door.

Sounds like Race with the Devil (http://www.terrortrap.com/killerthrillers/racewiththedevil/).

Heh--I mainly remember Warren Oates as Sgt. Hulka from Stripes, Kitkat22.