In a small New Jersey town, a radical fitness movement is under way.

The Morris Animal Inn has become the go-to fitness club for overweight four-legged friends.

The inn runs a weight-loss spa for overweight dogs because, just like people, American pets are battling an obesity epidemic.

Approximately 36.7 million dogs, or 53 percent of dogs in the U.S., are obese. And 43.2 million cats, or 58 percent cats in the U.S., are obese. Those extra pounds can cause some serious damage.

"It can contribute to orthopedic problems, respiratory problems, heart problems," said Dr. Kristen Frank, a veterinarian at the ASPCA animal hospital.

Lola, a mini daschund and member of the gym, is supposed to weigh 10 pounds, but she weighs more than double, at 21 pounds. At her heaviest, she was 28 pounds. Her owner, Roxana Sheikh, said Lola loves comfort food.

"If it's been a good day, have a treat. Feeling blue? Have a treat. It's caused a lot of extra weight," Sheikh said.

So Roxana brought Lola to the inn, where she and her canine friends run on a treadmill, jump hurdles, run up stairs, perform aerobic swims and finish off the day with relaxing water massages.

The pets are active, having fun, and in a safe environment.

But it's not just about moving those paws. A balanced diet matters, too. Experts say, make sure to measure pet food and lay off those fatty snacks.

Lola has already lost seven pounds since starting at the inn and has just 10 more to go.

"When you see her tail is wagging, her little feet are moving, she's not stressed, she's moving easily. It makes me very, very happy," said Sheikh.

ABC News