I've not read the book, nor seen the movie. But I gather there's a dog involved, and said dog goes from pup to old age. And dies, according to this spoiler - I sure hope not!
Do dog deaths upset you more than people deaths, fictionally speaking? I mean, often, the people had it coming - how many action films have you watched and witnessed hundreds of people's deaths with barely a shrug, or even, a thrill? Yeah! Dogs, on the other hand, are almost always innocent, and every dog death in fiction is tragic and heartbreaking. A weird imbalance, yes?