This one gets off to a ruff start and fails to ever get our tails wagging. When Molly Shannon and Kevin Nealon get their kid (Liam Aiken) a pet, they accidentally pick one that's part of an interstellar canine invasion crew that was sent to take over the planet. Yes, really. The two bond as we learn that our supposed enemies rather like it here on Earth but might have to leave soon.
It all leads toward a cliché, pull-out-the-tissues climax that has more bark than bite. There's little genuine sincerity, not many laughs and movie parents who don't even blink after witnessing a UFO--piloted by a cocker spaniel!--land in a grassy field. Though this might distract those young, easily entertained moviegoers for a few, for the rest of us, Good Boy! is a doggone disappointment.