Cujo

No. King has said he has no memory of writing Cujo because he was deep in his cocaine and alcohol addiction at the time. He learned about the book primarily from reading it after the fact—he has described it as a novel that 'happened' while he was in a blackout.

King has said the genesis was a visit to a rural Maine mechanic's garage, where a Saint Bernard came out snarling at him. He thought, 'What if my car had broken down here, alone, with this dog?' The survival-in-a-broken-car premise expanded from that single moment of fear.

Yes. Cujo is one of the core Castle Rock novels. The town appears in several other King works, and Cujo's events are referenced in Needful Things (1991), which is explicitly a Castle Rock story.

Parallel to the survival plot is the story of Donna Trenton's affair and her failing marriage to Vic. King uses the rabid dog as an extreme externalization of a family in crisis—the monster arrives when the marriage is already at its breaking point. The novel suggests the two disasters are not unrelated.

Yes. The production used five Saint Bernards, a mechanical head for close-up attack shots, and a stuntman in a dog suit for certain scenes. Training dogs to perform aggressively on cue—and then stop—required an extended preparation period. Director Lewis Teague and the animal trainers worked closely to make the dog's behavior believable without endangering the cast.