Stem-cell therapy for the treatment of joint diseases in animals, particularly dogs, cats and horses, has been available in the U.S. for a number of years. Today, second-generation technology is enabling more veterinarians to take advantage of this modality by making the investment less expensive and improving the process and delivery. Proponents say stem cells harvested from adipose tissue accelerate the healing of muscles and joints in adult animals suffering from osteoarthritis, hip dysplasia, ligament and cartilage injuries and other degenerative joint diseases. Researchers have found that “activating” stem cells before returning them to the animal’s body enhances the healing of these musculoskeletal problems. “This technology can be adapted for any animal, be it a dog, horse, cat or an exotic,” said Mike Hutchinson, DVM, owner of Animal General of Cranberry, near Pittsburgh. “We take that individual’s fat, process it and activate the stem cells. Then, we put them back into the same animal. We are using the animal’s own repair system, the adult stem cells.” Because it is an autologous procedure, he said, it is safe and effective. MediVet America of Nicholasville, Ky., is the company that sells the in-clinic equipment, adipose stem cell procedure kit and provides banking services for harvested cells. Hutchinson said MediVet’s recent improvements in processing have increased the number of stem cells collected, shortened the time from harvest to delivery because everything is performed in-house, and made the technology less expensive to the veterinarian. How It’s Done Stem cell therapy in animals starts with the harvesting of adipose tissue from the thorax or abdominal area while the animal is under general anesthesia. “The animal will be anesthetized for about 10 to 15 minutes,” said Hutchinson, a national spokesman for MediVet who has performed the procedure about 300 times. Then, the pet is awakened and kept in recovery while the veterinary technician extracts the stem cells. Once the cells are processed, the animal is sedated and the stem cells are injected into the affected joint(s) and given intravenously. Veterinarians need harvest only about 20 grams of fat—a little more than a tablespoon—to collect 400 to 600 million stromal cells, and the extra cells can be banked for future treatments, said Darren Marks, DVM, a partner at McGilvray Veterinary Hospital in Toronto, and a spokesman for MediVet Canada. Instead of sending the harvested tissue to a laboratory to separate the stem cells from the adipose tissue, this process now can be performed in the veterinary clinic. The harvested adipose tissue is broken down by an enzyme wash, then centrifuged to obtain stem cells. During the process, a blood sample is also taken and is centrifuged to separate contents and create platelet rich plasma (PRP). Rich in many growth factors, PRP is used in veterinary medicine, particularly in equine medicine, to aid tissue healing. The veterinary technician adds the PRP to the stem cells and puts the mixture under an LED light, which activates the cells outside the body. “We are using PRP and photostimulation, which activate the stem cells and cause them to proliferate in much higher numbers, and that is a big advantage,” Hutchinson said. “It also helps enhance the amounts of anti-inflammatory growth factors that are helping the body reduce pain and inflammation.” Once the fat is harvested, processing the stem cells takes about 21/2 hours, with the veterinary technician doing about 80 percent of the work, Marks added. Most owners report improvements in range of motion and mobility in three to 10 days. The stem cells will continue healing for weeks to months, and the effects last at least a year or more on average, Hutchinson said. Depending on the extent of the joint injury and the age of the animal when it first receives regenerative medicine, some animals will need periodic treatments. Hutchinson said it is important to frame owners’ expectations so they understand that the animal is suffering a degenerative disease, and that stem cells cannot “cure” arthritis. Instead, he said, stem cells will aid in healing, reverse some of the degenerative process and provide substantial pain relief, but over time, the joint will begin to degenerate again. It bothers him when people talk about getting their “puppies and kittens” back. “We are not turning a 10-year-old dog back into a puppy, but we are providing tremendous pain relief, so they feel better and they move around better,” he said. Getting Ready Because the patient undergoes general anesthesia, veterinarians are advised to perform an examination and pre-surgery blood chemistry. In addition, stem cell therapy is contraindicated in animals with malignancies, so experts recommend a radiograph of the chest and abdomen to make sure there are no tumors. Hutchinson said if the results show any abnormalities that would signal the animal might have problems with anesthesia, he might do more tests. For instance, an animal with a slightly enlarged heart or a murmur might be given an EKG. He likened the pre-surgery work-up to what an older dog receives before a dental. Small Learning Curve Veterinarians looking at this new technology tend to ask two questions: * Can I do it? * What are the side effects? Marks said the collection and processing of stem cells is already in the skill set of every veterinarian and every veterinary technician. “We all do surgery,” he noted. “We make an incision and remove the fat pad. I take it from the behind the shoulder; some people take it from the abdomen. Then, we hand the fat to the technician, who processes it. Technicians do lab work all the time.” The administration of stem cells is also simple. “Intra-articular joint injections can be tricky, but we’ve all been trained to do them, so most veterinarians just need to be reminded how to do them,” Marks said. When tissue is injured, damaged cells release chemicals to attract anti-inflammatory cells, so the stem cells will home in on injured tissue, even if the veterinarian misses the exact spot where the stem cells are needed when injecting the joint. MediVet recommends administering an intravenous dose of stem cells, which circulate around the body seeking inflammation. They appear to help other inflammatory conditions, Hutchinson said. “Owners come in and ask, ‘By the way, Dr. Mike, does this help the skin? Because my dog has allergies, but isn’t scratching as much,’” Hutchinson said. “As a result, researchers are testing the effect of regenerative medicine on immune system diseases like atopy and inflammatory bowel disease.” Veterinarians should watch for injection-site reactions and infection, although Hutchinson and Marks said that if the veterinarian follows basic infection control procedures, infection should not be a problem. “There is always a possibility that you can introduce infection when you inject a joint, so sterile technique must be used,” Hutchinson said. “But I’ve injected more than 900 joints, and I haven’t had one infection. We don’t expect a lot of adverse events with stem cells.” This Education Series article was underwritten by MediVet America of Nicholasville, Ky.
