Great part of the book. Cujo was going to attack but realizes its the boy. It's the last time cujo is able to reason

He was starting to go crazy but at this point had a sliver of self control left. He almost couldn't stop himself, but his love for the boy did overcome in that moment and he ran off quickly, seemingly knowing he would hurt the boy if he didn't leave right away. If he had seen the boy even a few hours later he wouldn't have been able to control himself at all.