Finally, a dog film that understands the bond between man and canine...doesn't exploit it, doesn't mock it, doesn't pretend it's more or less than what it is, doesn't milk it for mawkish sentiment. Marley & Me, which arrives on DVD shelves Tuesday, is about a couple and their dog. It's not filled with heroic events (Marley's no Lassie), or ceaselessly cute puppies. There's no talking dogs, no dog vs. cat staredowns. There's just a man and his wife, and the dog they come to love.