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One Dogs Stem Cell Venture

Retriever restored to health through medical procedure not yet done on humans.

Barbara Turnbull
living reporter

Jul 18, 2009 04:30 AM

Chip is a frisky, friendly 3-year-old chocolate Labrador. He's also a cutting-edge laboratory experiment.

While the promise of stem-cell therapies remain largely unfulfilled for humans, they are succeeding in leaps and bounds in dogs like Chip, whose transplant for his elbow dysplasia did what drugs, physio, water therapy and two surgeries could not. Elbow dysplasia, common in certain dog breeds, is a condition involving multiple developmental abnormalities of the elbow-joint.

"It's so exciting that they can do this," says Toronto resident Anne Molloy, about the April transplant of her pet's own stem cells.

Chip started limping at age 3 months, although he still loved to play and fetch, Molloy says. "You'd throw the stick for him and he'd start running, then buckle," she says. "We could never take him on a walk. It was very sad."

By a year his limp was bad enough that strangers constantly approached with concern and advice and he required a high dose anti-inflammatory and pain medication. After trying everything else, Molloy decided to try using her animal's own ability to heal itself.
The therapy, by San Diego's Vet-Stem, a company specializing in regenerative veterinary medicine, has been used successfully on horses since 2004 and dogs for the last 18 months.

About 3,500 horses and 2,000 dogs have been treated for hip and elbow dysplasia, osteoarthritis and tendon and ligament injuries, with success rates between 75 per cent and 95 per cent, according to survey results from veterinarians and owners, says company founder Bob Harman.
Here's how it works:

While the animal is under general anesthetic, several tablespoons of fat are extracted from the abdomen or behind the shoulder, which is shipped overnight to the San Diego lab. That's the worst part for the dog. On receipt of the fat, clinicians separate the stem cells from all other tissue, count the cells and divide them into proper doses within four hours, shipping one or two doses back to be injected into the joint the following day. The injection takes moments and is done under mild sedation.
Then magic seems to happen. The introduction of the stem cells to the injured joint signals anti-inflammatory cells and new blood cells to form.

It's expensive – about $3,500 – but cheaper than joint replacement, which costs up to $10,000.
Some 2,000 veterinarians are certified to perform the procedure in the U.S., but there are fewer than 20 in Canada. Its launch here was six months ago in Halifax.
"In our clinic, we're doing them almost every day, weekly certainly," says Dr. Christine Zink, a veterinarian and professor at Johns Hopkins University School of Medicine in Baltimore, and an expert on canine agility. Other treatments have low efficacy, particularly compared to this, she says.
Most animals show reduced lameness, pain and swelling and increased range of motion within two weeks of the transplant, though improvement continues for up to six months.

That's what happened to Chip, who perked right up, Molloy said.

Dr. Rona Sherebrin, of the Secord Animal Clinic, is the only vet certified by Vet-Stem in the GTA and practices at the clinic Molloy already attended.

"The fantastic thing about it is that it's using the dog's own tissue," Sherebrin says, eliminating transplant complications and the need for immunosuppressive drugs.

Most fat extractions provide enough stem cells for four doses. The remaining ones are stored, frozen, at Vet-Stem, for the future, Harman says.

And future injections are usually necessary. The transplant works for about a year in most dogs, which means one extraction is usually enough for older dogs.

Some dogs can go longer, depending on their activity level, Sherebrin says.

The procedure doesn't eliminate problems. Chip still needs some pain medication, but just a fraction of the high dose he required before. He also limps a little after hard play.

"If you've got a joint that's abnormal and you heal it, it's still got an abnormal shape and it's still going to end up having more tendency to arthritic changes," Sherebrin says.

The procedure is not approved in North America for people, although it's in clinical trials in the U.S., Europe, Japan and Australia, Harman notes.
Animal rehab

Animal rehabilitation has come a long way in a short time.

For example, the revolutionary stem cell injection can eliminate the need for joint replacements and heavy drugs, while easing pain and giving animals back their joie de vivre.

Treatments such as physiotherapy and acupuncture are as important for canine and equine athletes and other working animals as they are for beloved family pets. And demand is increasing, experts say.

Dr. Christine Zink, a Toronto-born veterinarian, professor and researcher at Johns Hopkins School of Medicine in Baltimore, Md., is one of 12 North American veterinarians guiding a proposal through the hoops required to create a new specialty of veterinary medicine – Veterinary Sports Medicine and Rehabilitation.

Zink, who was named the 2009 Outstanding Woman Veterinarian by the Association for Women Veterinarians Foundation, did her veterinary degree and a PhD at the University of Guelph, eventually becoming a board-certified pathologist.
The specialty will be the first new one in 20 years, she notes, and it's expected to be approved by the American Veterinary Medical Association in approximately a year.
"It fills a real gap in dog care that has long been filled in humans by sports trainers, orthopedic surgeons and physical and occupational therapist," Zink says.

Barbara Turnbull
Jul 18, 2009 04:30 AM