TOKYO - Even in a land of pampered pooches, Mayumi Niizuka's miniature schnauzers are considered spoiled.

Berun, 5, and Kilche, 6, get aroma massages and mud packs twice a month. They bathe in hot springs and dress in designer clothes. Combined with monthly veterinarian fees, Niizuka shells out more than $1,000 on the two pups, far more than she spends on her and her daughter.

"We may not be celebrities but we treat our dogs like one," she says, laughing.

She's now adding bimonthly oxygen treatments to the list.

The latest addition to Japan's $16 billion pet industry, dog spas are increasingly offering hyperbaric-chamber sessions, better known as medical therapy for athletes like Michael Phelps.

Veterinarians have long used oxygen treatment to aid recover for ailing animals, but Japanese spas are turning need into luxury, offering 10- to 30-minute sessions for weight loss and anti-aging. The most pampered animals sit in the capsules for basic R and R.

"Dogs are increasingly becoming a valuable part of the family," said Masahito Kitoh, the owner of Aspet, one of two companies selling the canine chambers. "Owners are doing everything they can to extend their lives, more than ever."

First launched by Japanese company Air Press in 2007, the capsules pump 100-percent oxygen at elevated pressures so the blood absorbs more oxygen, and speeds up the body's recovery time, Kitoh says. The treatments are now offered in more than 100 locations throughout the country for roughly $15 for a 10-minute session. Kitoh says they offer the same aerobic benefit as two hours of exercise.

At the swanky Wag Style dog spa in Tokyo, owners who are too busy to walk their pooches schedule sessions to breathe new life into lethargic dogs. The barometric pressure inside the capsules is equivalent to diving 7 feet under water.

"Lack of exercise, stress and obesity are all reasons [for the oxygen boost]," therapist Sanae Hagiwara said.

In real estate-challenged Tokyo, where dogs live in cramped quarters, Hagiwara says the capsules offer canines the perfect place to unwind.

Much like Americans, the Japanese have been known to coddle their pets, treating them to posh treatments, gourmet meals and couture fashion, with labels like Chanel and Dior offering luxury canine products. There are hot springs resorts for dogs, "strollers" to carry tiny lapdogs, anti-aging supplements and even doggy beer.

At Tsunayoshi no Yu spa in Tokyo's seaside neighborhood Odaiba, manager Hiroki Hayashi says customers regularly shell out hundreds of dollars each month for a makeover.

None more so than Niizuka.

She's admittedly not very keen on the scientific benefits behind the hyperbaric chamber, but she insists she's seen a difference in Berun and Kilche.

"They are so much more energetic," she said. "Plus, they have that extra shine in their fur now."

(Image Credit: Air Press)