Ruff! Road trip!

The moment K.C., a sweet, wiggly wheaten terrier, saw Brad Rogerino, her tail began thumping.

The dog knew what Rogerino's appearance meant - not just an affectionate scratch on the head, but a real adventure.

There are dog spas and dog bakeries, strollers to tote Fido, doggy day care, and even dog weddings. Americans will spend $43.4 billion on their pets this year, the American Pet Products Association estimates.

Enter Brad Rogerino, who last year started Doggy Adventures, a South Jersey door-to-door pet-exercising service that he plans to expand into Pennsylvania. For $26, he'll take Fido on a 90-minute day trip.

"I just saw the need for an extra little play group," said Rogerino, 28, who lives in Collingswood. "People are so busy - they're at work all day. This breaks up the day for the dog, and they get lots of socialization and exercise. It gives the dog something to look forward to."

Twice a week, Rogerino takes K.C. on an adventure with two other dogs he has carefully selected based on how well they socialize with the wheaten.

On a recent day, Rogerino arrived at owner Lisa Cover's sprawling home on a cul-de-sac in Hainesport, loaded K.C. into the specially appointed "doggy limo" alongside Heidi, a mutt, and Bruno, a Boston terrier-French bulldog mix. Tails wagged.

Then it was a short drive to Rancocas Creek State Park, where the fun began. Rogerino lifted the hatch, guided the dogs out one by one, and clipped each leash to his belt.

The pack started off slowly, then worked up to a brisk walk, three dog noses busily sniffing leaves and trees. Rogerino classified the bunch as "middle range" in terms of energy - dogs are grouped together not just by geography but also by stamina and temperament.

"This group stays together," Rogerino said, gently nudging Bruno's leash when he lingered too long in one spot. "They keep in their pack."

When the group came to a clearing, it was time for play - K.C. and Bruno chased each other in circles for five minutes, tails wagging, tongues hanging out, playfully pouncing on each other. Heidi, who's older than the others, stayed by Rogerino.

"She's just here for the walk," he said, rubbing her ears. "Yes, Heidi, we love you, too."

Still, Heidi has lost weight thanks to her adventures, Rogerino said, and dogs are definitely exhausted after he's done with them.

Rogerino might throw a tennis ball. If the weather cooperates, they might swim in Rancocas Creek.

On this day, Rogerino checked out the creek, but it was muddy from a fresh rain - a no-go.

"I do love swimming with them - I have fun until Bruno steals my sock and runs into the woods," he said, laughing. "You guys are so good."

Adventures happen rain or shine - dogs still need exercise, even in bad weather, he reasons, and clients appreciate not having to go out in the rain themselves.

The first few times Rogerino takes a dog out, he'll snap photos, then e-mail them to the owner so they get a sense of what their dogs do on a typical adventure.

It's a formula that has worked well so far, said Rogerino, who noticed a quieter, more tired bunch after a brisk run, then another cool-down walk.

As he popped the hatch of his Honda Element (outfitted with safety barrier, waterproof interior, carpet, toys, and doggy first-aid kit), the dogs jumped in.

"You guys did good," he told them, pouring tap water into blue plastic bowls.

He offered Milk Bones, and a clearly exhausted Bruno curled up in a corner. It was time to drive the dogs home.

Rogerino, 28, who used to work with disabled children and adults, always had an interest in business and an entrepreneurial bent. He also felt guilty about leaving his 10-year-old Labrador mix, Cassidy, home alone all day while he worked.

After studying the industry, he decided the pet business was robust, and that there was a market for something new - not day care, not simple dog-walking, but a step further.

He advertised in veterinarians' offices and at pet expos, and slowly built his client base to its current 50 dogs.

Terri L. Malueg-Ray, an Atlanta-based dog expert, said Rogerino's business is "at the cutting edge in the industry" - different from a pet taxi service or dog day care, filling a niche. She's heard of one other such service, in California.

"Any kind of stimulation is good - it de-stresses the dog, gives them something to do," Malueg-Ray said. "They get used to new people, riding in different vehicles, seeing new places. That makes a better dog who's more acclimated to a variety of sounds and smells."

The socialization is beneficial for most breeds, she said. Dogs who get such activity are easier to train and better around the house, she said.

These days, Rogerino, a lanky man typically dressed for work in khakis and Doggy Adventures fleece, begins his day around 8 a.m. and takes three or four separate groups on adventures, usually 10 to 12 dogs a day. He logs hundreds of miles a week on the Element, and knows every dog park in the area.

His clients are busy professionals, older people, young families - most every demographic you can think of, Rogerino says. Some ask him to come once or twice a week, some more.

And yes, the doggy limo pulling up in the driveway sends some canines into a tizzy.

"Some of them know the days I come. The clients tell me they have to be careful not to say my name, or the dog gets too excited," Rogerino said.

Count K.C. in that category. Her owner, Lisa Cover, got K.C. in February. Cover, 41, an administrator at Children's Hospital, works long days, and her husband, Paul, travels regularly for work. They didn't want K.C. to suffer because of their busy schedules.

At first, Cover tried dropping K.C. off at a doggy day care in Philadelphia, but she wasn't very excited about it.

"This is perfect," Cover said of Doggy Adventures. "She gets lots of exercise. We think Brad provides just such a great service. It's a good business model."

Cover loves that K.C. runs and swims regularly, and she thinks the dog's behavior is better as a result of regular day trips.

"We knew that as long as K.C. gets enough exercise, she'd be a great dog, and she is," Cover said. "She just loves it."