The widespread veterinary use of stem cell therapies in past years well demonstrates that there is no good reason for regulatory barriers blocking human application of these technologies: "Vet-Stem, a Poway, Calif.-based company, is developing the stem cell therapy and began treating horses in 2003. It derives stem cells from fat samples taken from dogs and horses across the country. The procedure has been used mainly to treat osteoarthritis, which involves loss of cartilage in the joints, but Vet-Stem is researching treatments for other diseases. Vet-Stem claims the therapy enables animals to replace cartilage and other tissue. Since 2003, the privately held company has treated 3,500 horses and 1,500 dogs and plans to begin treating cats later this year. More than 1,500 vets are licensed to use the procedure. ... Really, all we're doing is harnessing the existing repair machinery in the body, concentrating it, and putting it right where an injury occurs, where healing is needed, to heal naturally. ... One peer-reviewed [study] sponsored in part by Vet-Stem, found that tendinitis in horses was improved by injection of the adult stem cells. Two other studies published in Veterinary Therapeutics found that dogs with osteoarthritis showed improvements in lameness after stem cell injections. Those studies also were sponsored by Vet-Stem and conducted by Vet-Stem researchers and other veterinarians."