A 9-month-old boxer pup named Duncan barrelled down a beach in Oregon, running full tilt on soft sand into YouTube history and showing more than 4 million viewers that he can revel in a good romp despite lacking back legs.

“It’s a heartwarming, wonderful thing to see,” said Dr. Bonnie Beaver, a professor at Texas A&M University’s College of Veterinary Medicine and executive director of the American College of Veterinary Behaviorists.

More veterinarians are using wheelchairs, orthotics and prosthetics to improve the lives of dogs that have lost limbs to deformity, infection or accident, experts say. There have been great strides in technology to keep up with U.S. soldiers returning wounded from war, and veterinarians have adapted the materials and know-how for the rising demand from clients.

“There are so many things we can do to solve mechanical problems. ... If you have broken parts, we can replace them,” said Martin Kaufmann, co-owner of Veterinary Orthotics and Prosthetics in Denver, also known as OrthoPets, which helps about 2,000 animals a year.

Most devices range from $150 to $2,000 but can cost more, Kaufmann said.

Duncan’s owners, Amanda Giese and Gary Walters, are co-founders of Panda Paws Rescue for special needs and hospice dogs in Vancouver, Washington. Of the 3,500 dogs they have placed in the last 19 months, 10 were two-legged. Nine of them adapted to wheelchairs and found homes.

Only 19-pound (8.6-kilogram) Duncan, whose deformed back legs were amputated, refused to take to wheels.

But they have seen successes even in challenging cases, Kaufmann said. Orthopets helped mixed-breed puppy Naki’o after his four legs and tail were frozen in ice. What frostbite didn’t do, a surgeon did, amputating all four legs. Then, Kaufmann outfitted him with four prosthetics.

“To see Naki’o at the beginning, he was protective and guarded,” he said. “Six months after all this was done, he was just a fun-loving guy who likes to socialize.”

Another dog, a Labrador-golden retriever mix named Pirelli had a back paw that never developed.

Pirelli uses a prosthetic limb, and with it is a “happy, expressive dog, able to run and play, retrieve things and eat his food,” said Dudley Arnold, Pirelli’s handler.