TL;DR: The dog is shot at the end of the movie. (Fun facts about filming at the end!) In the opening scene Cujo is bit on the nose by a bat and whimpers and yelps. From this, he contracts rabies and starts behaving abnormally. He whimpers at loud noises and is seen with foam at the mouth and blood on his face. He begins to attack people and they try to fight back with fists, bricks, and baseball bats. Cujo performs several impressive stunts like ramming his head into a car and jumping through windows. At the end of the film, he is beaten with a baseball bat and seemingly stabbed with its broken handle before ultimately being shot. BUT some fun facts about filming that might make this easier to watch!! There were several dog actors on set, and they all did such a good job! Filmmakers had to take care not to get their wagging tails in the shot since they were so excited to be there! In the scene where Cujo was trying to get in the car, they put the dog’s favorite toys inside to get those shots! And the foam coming from his mouth was egg white (which is healthy for dogs to eat), and they couldn’t stop licking at it since it was so yummy! Lastly, of course, in the shots where Cujo was attacking or performing dangerous stunts (close ups and ramming his head into the car), a man in a dog suit or a mechanical dog head was used.