And, as he proved in his previous film, Waiting for Guffman--and continues to prove with Best In Show--writer/actor/director Christopher Guest works firmly in the same tradition, showing us a gallery of American obsessives who never quite realize that their obsessions are sidesplittingly absurd. In Guffman, Guest examined the dreamers who populate community theater from Baltimore to Bakersfield. In Best In Show, it’s dog owners, hoping their pooches will be declared top....er, dog...at the fictitious, yet all too real, Mayflower Kennel Club Show in Philadelphia.

As in Guffman, Guest collaborated on writing his “script” with Eugene Levy, alum of the immortal SCTV and a man whose humor is in sync with Guest’s high wire approach. “Script” is in quotes, because what Guest and Levy do is create a roster of characters, sketch a firm arc of the storyline, and then recruit performers capable of improvising effortlessly within the framework of a faux documentary. Because nothing is so bad as bad improv, this is risky filmmaking, so Guest and Levy pick proven collaborators. Among the lead and supporting actors (including the authors) are Catherine O’Hara, Fred Willard, Michael McKean (who with Guest was 2/3rds of Spinal Tap), Parker Posey, Bob Balaban, and Ed Begley, Jr., along with some lesser known names who mesh beautifully, all the way down to the uncredited (in the production notes) Asian-American actor portraying a pet shop proprietor who must endure Posey’s rampaging yuppie from hell in search of a squeaky bee toy to placate her ill-mannered Weimaraner.

The virtue of Guest’s approach is that it can create marvelous individual scenes of comedy. The vice of his technique is that, when scenes don’t really work, or go on too long, Best In Show gets out of rhythm. During the climactic dog show, for example, Guest too often resorts to scenes between Fred Willard and Trevor Beckwith, who play the show commentators. At first (and maybe second and third), Willard’s classless, clueless comments about the proceedings, such as his riff on pronouncing “Shih Tzu” are are funny, but Guest relies on Willard far too much--probably because the only other possible action is watching dogs prance around a ring.

What works most successfully are the scenes which set up the dynamics among couples who are competing together. Scott Donlan (John Michael Higgins) and Stefan Vanderhoof (McKean) are a gay couple who came together over their love of dogs--Donlan’s a young, professional, ultra-flamboyant dog handler and Vanderhoof a beauty salon owner who paternally indulges his partner’s outrageousness. Gerry and Cookie Fleck (Levy and O’Hara) are a barely middle class Florida couple so devoted to their Norwich terrier Winky that they write songs about her. (Cookie is also a woman with a past--or about 5,000 pasts. Everywhere the Flecks go they run into ex-boyfriends given to graphic reminiscences.) Meg and Hamilton Swan (Posey and Michael Hitchcock) are wealthy lawyers whose seeming devotion to their dog is only exceeded by their love of earth tones, Macintosh laptops, Starbucks, and the J. Crew catalog--they prefer shopping by phone because, “You don’t have to deal with people. Except for the operators.” (Extra style points go to whoever thought of giving the Swans braces for their teeth.) And Sherri Ann Cabot and Christy Cummings (Jennifer Coolidge and Jane Lynch) are the voluptuous owner and mildly butch handler, respectively, of reigning champion Rhapsody In White.

But perhaps the most intriguing character is Guest’s Harlan Pepper, a fishing shop owner from North Carolina who has journeyed to Philadelphia with his bloodhound Hubert. With brush cut hair and a thin moustache, Guest makes Harlan a quiet figure of considerable dignity, rather than the stereotypical good ol’ boy. In the dog show world, where panic and adrenalin role, Harlan’s calm is almost Zen-like, although his passion for ventriloquism would likely baffle even the Buddha.

Before the winner of the coveted “best in show” title is declared, there is even a 42nd Street style moment when an understudy (human, that is) has to go on as a handler and become a star. That’s in keeping with the best show business tradition and, as Christopher Guest and his merry band demonstrate, the dog show is definitely a form of show biz, one in which the only sensible participants have cold noses.