Stem cells will hopefully change a leopard’s knee, not its spots
Deborah Smith SCIENCE EDITOR
November 20, 2010
…WHEN you are born to leap up rock faces that are almost vertical, an arthritic knee can be more of a pain than usual.
That’s why one of Sydney’s snow leopards, Kamala, has become the first big cat and first zoo animal in the world to undergo a new stem-cell therapy aimed at preventing further degeneration in her joint.
Her extremely long, thick, furry tail hung down from the operating table at the Taronga Zoo Wildlife Hospital, as the surgeon, Tony Black, collected a wad of fat from her belly.
After it had been processed in the hospital lab, the fat, which contains large numbers of stem cells, was injected back into her right hind knee joint.
A hospital veterinarian, Kimberly Vinette Herrin, said it was decided to try this new approach after traditional treatments for the five-year-old snow leopard, an endangered species, had limited success.
”Because she is such a young animal we want to try to slow down the progress of the arthritis. We want to give her the best quality of life and alleviate any pain or discomfort,” Dr Vinette Herron said. This two-hour procedure has been used on a few cats and more than 250 dogs with osteoarthritis in Australia and New Zealand. Vets and pet owners have reported improvements in mobility and pain in 80 per cent of cases.
Seven people have also had the therapy, and a double-blind clinical trial of 40 people in Sydney is about to start.
Kamala and her male sibling, Sabu, both developed a rare condition in cats called osteochondrosis when they were about six months old.
The developmental disorder, which leads to a flap of cracked cartilage, is thought to be genetic but is also related to diet and rapid growth.
Dr Black, of the Veterinary Specialist Centre in North Ryde, operated on both snow leopards when they were young to remove damaged cartilage and bone. ”The brother has done incredibly well,” he said.
Kamala, however, has developed a slight limp, which drugs have not improved.
Ben Herbert, of Macquarie University, who developed the AdiCell therapy with Graham Vesey, chief executive officer of Regeneus Animal Health, said the biggest improvement is seen at about 10 days, and had lasted for two years in treated dogs.
The injected sample contains a range of cells including mesenchymal stem cells. Their main effect appeared to be to decrease inflammation and secrete growth factors that promoted tissue healing, Associate Professor Herbert said.
Results from 26 dogs that have been treated with the therapy, which costs about $3500, have been submitted for scientific publication, but more research is needed. ”We don’t understand why some don’t respond. It doesn’t appear to be related to age or stage of disease.”
Dr Black will be involved in two new trials with dogs where improvements will be assessed using a pressure-sensitive walkway.
Estimates of snow leopards in the wild range from 2500 to 7000, with 600 to 700 in zoos. They are a target for poachers, with their luxuriant grey spotted fur often used to make a traditional Tibetan coat. They have the longest tails of any cats, which they wrap around their young in the snow, like a muff.