A prominent underbite and bulging eyes won’t score a dog many points at traditional shows, but they can earn him the title at this one. Since 1976, the World’s Ugliest Dog Contest has celebrated the appearance of dogs who don’t quite conform to the traditional notion of beauty. But though the desirable traits may be different from other contests, filmmakers Don Lewis and John Beck found that the behind-the-scenes drama can be very similar.

“It’s a lot more competitive than we expected it to be,” says Lewis, who chronicled the contest, along with Beck for the documentary “Worst in Show,” which recently came out on DVD. The film follows four homely hounds and their owners as they gear up for the 2010 contest. Each summer, owners from around the country take their dogs to the Sonoma-Marin Fair in Petaluma, Calif., to compete for $1,000 — and lots of media attention.

For the owners, it’s mostly about the fame,” Lewis says. Much like the characters in the fictional documentary “Best in Show,” the owners take the contest very seriously, he says. The film plays up the rivalry between Pabst, a Boxer-mix that was rescued from a shelter, and Rascal, a purebred Chinese Crested. “Things got pretty intense between the owners,” he says.

Although the comparison to kiddie pageant is inevitable, Lewis is quick to point out that the dogs aren’t required to perform complicated tricks and that their appearance is all natural. “There’s no makeup,” he says. The dogs are also examined by a veterinarian to make sure that their unusual appearances aren’t a result of poor health.

Lewis says that the best discovery he made during the course of filming was that many of the contestants had been adopted from shelters. “That was a nice surprise,” he says. “Along with all the fighting between the owners, there’s a heartwarming story of animal rescue, which was unplanned and amazing.”

“Worst in Show” was just released on DVD. For more about the film or to order a copy, go to www.worstinshowmovie.com