Parents need to know that “A Dog’s Purpose” is an emotional drama based on W. Bruce Cameron’s 2010 novel about a dog that’s reincarnated several times from the 1950s through the 2000s . There are some violent/upsetting scenes: An alcoholic, abusive father pushes his wife and son; a man kidnaps a girl, threatens her, throws her in the water, and shoots at a police officer and his dog; a neglectful dog owner keeps his dog chained and then purposely lets him go astray; and a fire causes a catastrophic injury for a young man.