LOS ANGELES - The Shih Tzu is a whirl of fur on a course studded with obstacles, flying through tunnels, leaping over bars, scrambling up bridges and zigzagging through poles as its owner tears alongside, calling out commands and flashing hand signals. At the finish line, there are hugs, treats and lots of slobber.
Linda Harper of San Diego and her Shih Tzu named Fame spend every weekend on the road competing in agility races, the fastest growing dog sport in the United States that is most popular with older pet owners. Harper, 67, says the whirlwind contests help her and her dogs stay young and fit.
Harper has eight minutes to memorize the 18 to 20 obstacles before the clock starts ticking. That's far longer than Fame gets to scramble through it - the standard time for a dog to finish a course is 50 seconds.
This isn't a walk in the park - it's a heart-pounding, high-flying sprint. Owners must guide their dogs through the obstacles in a particular order, and do it as quick as they can. There are penalties if a dog walks on top of a tunnel, enters the wrong end first or knocks down a bar.
Veterinarians say the exercise and camaraderie are beneficial for dogs, and the more popular the sport, the safer the equipment. The newest gear is lightweight, breaks away if a dog hits it and has no sharp corners. And pooches are never asked to jump higher than their legs will allow.
"Any dog that enjoys exercise and working with their owner can excel. If the dog seems to enjoy the sport and the owner is having fun, it is a good thing," said Dr. Bonnie Beaver, a professor at Texas A&M University's College of Veterinary Medicine and executive director of the American College of Veterinary Behaviorists.
When handlers describe the joys of agility, they talk about the euphoria of a perfect run, being in sync with their dogs, making friends at competitions and getting to travel.
Gayle Lape, 71, of Catonsville, Maryland, called competing with her Pembroke corgis, Phoenix and Ruddy, "a passion, an obsession." She says she's "so happy I am still able to do this. I am enjoying the ride and the run."
As Lape and her dogs have aged, they have changed the way they work. She sometimes teaches her dogs to ignore her while she takes shortcuts.
The American Kennel Club surveyed competitors last year, and 50 percent said they were over 51 years old. Of those, about 20 percent said they were over 60. To attract young people to the sport, entry fees are sometimes waived for handlers under 18.
The club is the largest of nine U.S. groups sponsoring agility trials. Purina Pro Plan's Incredible Dog Challenge televises many of events and helps introduce newcomers to the sport.
The number of agility participants has grown every year since it was adopted by the American Kennel Club in 1994, and it's up 48 percent in the last five years, said Carrie DeYoung, the club's director of agility. To a lesser extent, there has been growth in other dog sports, too, including dock diving, where dogs jump for height or distance into water; Frisbee, both distance and freestyle catching; and herding.
Lape and Harper enjoy winning but say their dogs only care about pleasing them.
"It is very unlikely that they (dogs) care about winning," said Beaver, the veterinarian. "Owners may think they are working harder in competition, but it is actually the owner who is working harder and the dog is responding to the owner's cues."
Despite the thrill of a win, no one gets into agility for money, DeYoung said. Even in major contests, top prizes rarely exceed $1,000, she said.