Whoever said "Children are for people who can't have dogs" had it half right. Because, as Nora Ephron quipped, if you have teenagers it's important to get a dog so someone is happy to see you when you get home.

In Marley & Me, the frisky yellow Labrador named for reggae master Bob Marley is always happy, tail-waggingly so, when he hears the voice of his master, John (Owen Wilson). As Marley is the alpha in the relationship, it is probably more accurate to call John his man.

Based on the best-selling memoir by John Grogan, a former columnist for The Inquirer, Marley & Me operates on the assumption that happiness is a warm tongue bath. And those who endorse this belief will enjoy this shaggy dog story.

By shaggy dog, I mean that


is both a tale about a nappy canine as well as a long-winded yarn in which nothing - and everything - happens.

The anecdotal structure does not make for a gripping movie. For one thing, there's no conflict, unless you count the tension between a guy and his untrainable pooch. Yet Marley boasts animal magnetism.

Director David Frankel (The Devil Wears Prada) cultivates this, maintaining his focus on how the dog changes people rather than on how people change each other. Wilson, whom I've long thought of as a two-legged retriever, spends more screen time talking to one of the 22 dogs that play Marley, confiding fears and hopes, than he does with nominal costar Jennifer Aniston.

Mawkish? Sometimes. But often very funny and occasionally very moving. Frankel's film distills the essence of the dog/man relationship: Because of their accelerated life cycle, dogs show humans how to give unconditional love - both when bouncing with energy or when riddled with arthritis.

The film opens with the wedding of ambitious Jenny (Aniston) and lackadaisical John, both journalists. She actively organizes their life, he passively takes things as they come.

When John senses that the next step on Jenny's to-do list is to have a baby, he gets her a dog, a more convenient object of her maternal impulses.

Aniston, Wilson and the straw-colored puppy look like a family - or at very least, like creatures who consult the same colorist. In the movie Marley helps the Grogans rehearse parenthood: As a couple they learn to care for this creature.

What they do not learn is how to set limits for this pillow-shredding, bra-chewing, turkey-stealing pup, an omnivore with an insatiable appetite that ranges from drywall to mangoes.

The comedy in the film springs from Marley's misbehavior, which is epic.

The heart of the film is in the relationship between human and canine. Dogs are witnesses, confidants, companions, confessors, consolers. They bark, but don't talk back. They are empathy on four paws. In their bottomless eyes we see ourselves reflected, imagine ourselves understood, our families united.

Humans impute all kinds of such intelligence to dogs. (Herman Melville gushed that "no philosophers understand us like dogs and horses.") And Marley made me project these kind of sentiments onto the pooches who played Marley. Ordinarily, when I look into the eyes of a dog, I don't read "love, love, love," but "treat? treat? treat?"

The humans, particularly the wistful Wilson, deadpan Alan Arkin (as Grogan's editor) and Nathan Gamble, a 10-year-old who plays the eldest Grogan child, are very affecting. Aniston, who has great offbeat comic timing, doesn't quite find her rhythm here.

The PG film is suitable for those 8 and older. Parents, be warned: There is discreet candor about human sex and pregnancy, a brief glimpse of dog humping, and themes of mortality.