When pets have osteoarthritis, OA, veterinarians often recommend the same treatment plan that humans with OA are encouraged to follow: weight loss, exercise and nonsteroidal anti-inflammatory drugs, NSAIDs. But when these traditional methods of arthritis treatment fail in their dogs, some pet owners are turning to an option not yet available for people – stem cell therapy.

In the cutting-edge treatment, a veterinarian surgically harvests about two tablespoons of fat cells from the dog’s body and sends them to a lab. After the stem cells are isolated and returned within 24 hours, the vet injects them back into the dog’s joints that have arthritis.

The hope is the injected cells will regenerate damaged joint tissue, but once they are injected it is not clear what they are doing in the joint, says Farshid Guilak, PhD, professor of orthopaedic surgery and biomedical engineering at Duke University Medical Center in Durham, N.C. A growing number of researchers, including Guilak, suspect they may help by reducing inflammation.

"There is a theory that is getting more and more support that these stem cells produce anti-inflammatory cytokines," says Guilak, who is studying stem cells in mice with arthritis.

Regardless of how the treatment might work, many pet owners are convinced it does. According to pet-owner surveys conducted by Vet-Stem, the only U.S. company that is currently processing fat stem cells for veterinarians, approximately 75 percent of dogs treated for arthritis have an improvement in quality of life after the treatment with possible relief lasting anywhere from six months to one year. 

For veterinarians, however, the jury's still out on the therapy's usefulness. Some veterinarians don’t believe the cost – approximately $3,000 – as well as the risks that accompany any surgical procedure, are worth the limited success rate.

“We don’t know if it’s even as good as NSAIDs [at relieving pain] and it certainly costs a lot more,” says James Cook, professor of orthopaedic surgery at the University of Missouri College of Veterinary Medicine in Columbia. “Until I see a lot better evidence, we don’t use it and I don’t recommend it.”

But Darryl Millis, professor of orthopaedic surgery at the University of Tennessee College of Veterinary Medicine in Knoxville, sees the benefits of stem cell therapy, most notably for dogs that have not been helped by traditional means for relief.

“We’ve done it on severe cases that had already gone through all the basic treatments,” says Millis. About three-quarters of the dogs responded well, showing less signs of pain and being much more active, he says. “It is fairly costly but a lot of people are willing to spend that to have their pets lead a less painful life.”

Might the same therapy be useful for people seeking a less painful life?  Possibly – but not for a while, says Guilak. "It seems promising, but it is very preliminary." Before using it in people, he says, doctors would need to better understand how it works and how to maximize results.