PORTLAND – Maureen Lafferty is anti-fur. Anti-fur in her tub. Anti-fur on her towels. And anti-fur in the drain.

That’s why she and the one big ball of fur she does love, Jackson, a yellow Labrador retriever, are patrons of the Portland Dog Wash.

“This is why I don’t do this at home,” Lafferty said, pointing to big clumps of fur at the bottom of the stainless steel basin.

In a country whose residents spare no expense on their pets, self-service dog washes represent another splurge, allowing dog owners to forgo the indignity of chasing a wet and soapy dog around the house, or across the lawn, along with the messy cleanup.

The trend kicked off more than a decade ago. Now it seems that just about every sizable city has at least one.

In Maine’s largest city, the bustling Portland Dog Wash has five tubs, which are disinfected after each wash.

“This setup is much easier than doing it at home,” said Lafferty, who wore a standard issue vinyl smock while tending to her 9-year-old dog.

There are more than 70 million dogs in the United States, and they account for a good chunk of the nearly $3 billion pet owners spend each year on grooming and boarding, according to the American Pet Products Manufacturers Association.

Dog washes are a natural as dogs increasingly become part of the family, living inside homes instead of dog houses, eating hoity-toity designer pet food, going to doggie day care and traveling with families on vacations.

“I don’t think it’s a trend that’s going to go away,” said Blair Smith, who has helped to open three Dirty Dog locations in four years in Austin, Texas. “People are not going to stop spending money on their pets.”

The idea was born out of many a pet owner’s frustration.

Washing a dog, especially a big one, is messy. The dog shakes. Dirty, soapy water splashes on the walls. Your knees, your back or both hurt from kneeling next to the bathtub. Then there’s the big lump of dog hair in the drain.

That’s what was on the minds of Francisco and Gloria Gamero when they opened their first dog wash 15 years ago in Santa Clarita, Calif. They now have three U-Wash Doggie locations. U-Wash, like Dirty Dog, offers franchising opportunities.

“Up until we opened our store, there was no facility like ours in the United States. Now they’re everywhere,” said Andres Gamero, the couple’s son.

In Portland, Mark and Greg Goodwin got the idea after hearing from a friend about a dog wash in the Baltimore area. “We just dove into it,” Mark said.

Their business features waist-high tubs with all the accessories close by – combs, shampoos, conditioner, perfumes, towels, hair dryer. There are eye wipes and ear wipes and even dental wipes with a minty scent.

It’s a simple concept. Customers are willing to pay from $8 to $16 – the price is based on the size of the dog – to let the Goodwins sweat the details.

Although some might consider it a splurge, it’s far less expensive than taking a dog to a professional groomer. On average, self-service dog washes charge 30 percent to 50 percent less than the cost of a professional groomer, according to Stephen Mart from PetGroomer.com in Yelm, Wash.

As with any good idea, there are variations on the theme. Some, such as California’s U-Wash Doggie, offer professional groomers in addition to self-service washes. Others aim even higher, or farther over the top, depending on your point of view.

In Portsmouth, N.H., the Club Canine Dog Wash and Spa lets owners lavish their pets with blueberry facials and bubble-bath paw treatments, even canine massage and Reiki, a Japanese stress reduction technique using touch.

“It’s a little new agey, I know, but people are doing it for themselves. Because their pets are also part of the family, they’re doing it for their pets too,” said Stacey Kimberly Rogers, co-owner of the business.

If that seems too serious, dogs can lighten up with a monthly “yappy hour” where they can socialize over a bowl of nonalcoholic, no-fizz, beef-flavored “Happy Tail Ale.”

“Fun is the operative word. You’ve got to have fun,” Rogers said.

Mark Goodwin agrees with the idea of having fun, but said reducing stress is important, too. He said he and his brother launched their dog wash idea partly because Mark was feeling stressed out by his primary job as an environmental consultant.

They’re trying to keep it fun, even though this is the busy time of the year because it’s getting cold outside.

As for Lafferty, she can’t imagine any other way of washing her dog and said she would be at a loss if the Goodwins ever went out of business.

“We’d either find a new place to wash him, or we’d have a really smelly dog. Ultimately, we’d find a new place to wash him,” she said.