Devil Dog: The Hound of Hell

http://en.wikipedia.org/wiki/Devil_Dog:_The_Hound_of_Hell        The Barry family acquire a new puppy after their old one dies in an accident. They buy the puppy from a seemingly friendly fruit vendor who is actually a satanist who bred the dog during an evil ceremony, causing it to be possessed. They sell the dog to wreak havoc in the hope Satan will overcome good once and for all. The dog acts very strangely when they bring it home, leading the father and the family maid to believe there is something wrong with the dog.Eventually, the family's souls are possessed by the hound causing them to act strangly, including the son framing a student by stealing a watch and planting it in a classmate's locker, allowing him to win the student election. Dad decides the dog has overstayed his welcome when he finds a secret shrine to Satan in the attic. Dad tries to shoot the demonic beast to put an end to the hardships, but it is unharmed. Realizing the dog is possessed, the father finally makes a special trip to Ecuador to determine how to destroy the animal. Unfortunately, there is no way to kill it