From a small office on Whidbey Island, a company is giving pets that have lost use of their legs renewed mobility.

And business is booming for Freeland-based K9 Carts.

The company is the first of its kind in the United States — perhaps the world — to sell what amounts to wheelchairs for animals, according to owner Barbara Parkes.

The company builds support chairs for pups, cats, mini horses and just about any animal imaginable that was either either born with a disability or somehow lost the function of their legs.

The carts are made from lightweight material, primarily metal, some plastic pieces and wheels that vary in size depending on the cart. The wheelchairs are built quickly enough that the company sells around 50-75 per week.

Depending on size, costs range from $225 to $525, or $75-$175 for rentals.

It’s a service that Whidbey Island, let alone Western Washington, is lucky to have when a pet starts to lose function of its legs, said Bellevue resident Howard Eng.

Eng recently took Roxy, his 13-year-old Cavalier King Charles Spaniel, into K9 Carts.

Roxy’s legs started to atrophy a few weeks earlier.

“I read online they’re one of the top companies that do this,” Eng said.

The carts are typically made for the hind legs of an animal, though the design team can make contraptions for front legs and full support carts. They are customizable to each animal.

Recently, Parkes and her crew built a cart for a 90-pound turkey that fractured its legs after jumping from a dog house.

Accommodating even the strangest pets gives K9 Carts an edge over competitors, Parkes said.

“No matter how much you see, you always see something different,” Parkes said. “You never know what’s going to walk through the door.”

Parkes said companies around the world try to mimic her business model, but said K9 Carts’ solid reviews online and some 40 years of experience provide an competitive edge.

“It’s not just about selling a product, it’s about caring for the pets and the owners,” Parkes said. “I almost think it’s not a business per se, but a way for me to improve the lives of pets.”

Business has been so good for Parkes that she now employs eight people — four in the shop, two in the administrative office and her son and his wife who live in Florida but help with designs.

And Parks projects more growth.

“We’re still on an upward trajectory,” Parkes said. “Glenn [her son] is designing a new website which will drive business. We also have an 800 number to call for customers around the world.”

K9 Carts was founded in Pennsylvania. Originally from Scotland, Parkes was doing administrative work for an animal hospital at the time and saw countless animal surgeries done. Her ex-husband was also one of the first veterinary orthopedic surgeons in the country.

Parkes said there is a time limit for doing back surgeries on animals, particularly dogs. Otherwise, they lose their mobility and have to drag themselves from place to place in a miserable stupor.

Parkes first went to a friend and handyman to build a wheelchair for dogs. She liked what she saw and started the business out of her garage.

She took it with her when she left for Montana before finally settling in Langley.

Forty years has passed since then, and she still loves her job as much as ever.

The reward, Parkes said, is in helping the animals and seeing the reactions from the owners when their pets’ mobility is improved almost immediately.

Pet owners like Howard Eng.

“In the last couple of weeks, Roxy couldn’t even walk 10 feet without stumbling,” Eng said. “It still didn’t look good at the beginning of the session, but once they modified the cart she did so well.

“To see her do that again was great.”