Cujo

A family's two-hundred-pound Saint Bernard is transformed by rabies and the insidious guidance of demonic forces into a terrifying monster. Cujo (/ˈkjuːdʒoʊ/) is a 1981 psychological horror novel by American writer Stephen King about a rabid Saint Bernard. The novel won the British Fantasy Award in 1982 and was made into a film in 1983. Acute family dog turns into a vicious family killer in King's canine classic