Every dog has its day and in this case it's a pack: Winky, Beatrice, Rhapsody in White, Miss Agnes, and Hubert, all well-bred bowsers, better bred than their owners, a strange assortment of dog lovers whose own quirky identification with their trophy pets is never kept at leash length. Director Christopher Guest, who also plays Harlan Pepper, an aspiring ventriloquist with a bloodhound, modeled his “dogumentary” on the Westminster Kennel Club and its preening pedigrees. The straight poop on this competition is handled by Fred Willard as the ingenuous “color” commentator. AKCapproved, Best in Show is a breed all its own.