Los Angeles district attorney Tim Allen keeps turning into a sheepdog and back again in this Disney comedy, which lifts its title from the 1959 original but more of its story from the 1976 sequel, The Shaggy D.A. Even as a man, the hero wrestles with canine traits, though this being a PG-rated movie, we’re denied the pleasure of seeing him mark his territory and hump people’s legs. The laughs dry up whenever he assumes his alternate form and the script shifts from physical comedy to doggy one-liners. But for a kids’ picture this is relatively funny, buoyed by Jane Curtin as a bitchy judge and Robert Downey Jr. as the preening corporate villain. Brian Robbins directed; with Kristin Davis, Danny Glover, and Philip Baker Hall. 99 min.