The Shaggy Dog may not make you howl, but it does offer a few bona fide belly laughs, which is more than the last few Tim Allen movies could boast.

Allen plays assistant district attorney Dave Douglas, who is prosecuting an animal-rights activist for a fire set at a mysterious medical lab.

A genetically mutated dog escapes from the lab and is taken in by Douglas' family. Douglas, no fan of dogs, is bitten and gradually transforms into a part-time dog.

The dog that bit him is no ordinary genetically altered pup. He's a 300-year-old meditating Tibetan canine that was taken from his Himalayan home by nefarious types who want his DNA for experimentation.

This ultra-PC remake bears little resemblance to the 1959 Fred MacMurray version, which was about magic and heroism.

Dog is funniest when Allen first exhibits canine traits. He scratches frantically behind one ear, sticks his head out the window while driving, chases his bathrobe belt as if it were a tail and regards his kitchen as a paradise.

But the movie goes awry by trying to deliver an uplifting message. Douglas is a workaholic who is clueless about his kids' talents and deficiencies. Kristin Davis plays his sweet, bland wife, who is increasingly disgusted by her husband's inattention. His kids (Spencer Breslin and Zena Grey) resent but accept his role as an absentee dad.

Morphing into man's best friend teaches him a thing or two about being a good father. Huh?

Robert Downey Jr. has a weirdly funny, over-the-top part as an ambitious doctor who is double-crossing the lab's founder (Philip Baker Hall). Danny Glover is the district attorney, and Jane Curtin plays a judge; the small roles don't make much use of their abilities.

The movie is all about Allen, who delivers capably when it comes to physical comedy. A scene in which he chases a cat while on all fours as his human self has its moments of slapstick humor.

Allen would be wise to give up the holiday sapfests (alas, The Santa Clause 3 is due this year) and concentrate on what he does best: silly, broad humor. His life as a dog provides fairly entertaining escapist family fare. But if you're seeking subtle wit and an intriguing plot, you're barking up the wrong tree.