“A Dog’s Purpose” (*** out of four) was a bittersweet story about a dog who attempts to discover his meaning and purpose in life over the course of several lifetimes and owners (Dennis Quaid, Britt Robertson, Kwitt Ameyaw). The dogs are all adorable and are “great actors” and film has a heart-wrenching climax but film wavers uneasily between an innocent children’s film and a downbeat adult story about separation and loss. Many nice moments however and film is beautifully photographed enough to make it worthwhile for both adults and kids. Game effort by director Lasse Hallstrom, even if this falls short of some of his best work (“What’s Eating Gilbert Grape?”, “Once Around.”)