By Julie Power
Therapy dog Leo appeared happy to be patted and stroked by nursing home residents with dementia until he started showing symptoms eerily similar to theirs.
Leo would forget where his food bowl was located or he'd wait at the wrong door when the door bell rang, said his owner Fiona Gibbs of Pymble. Initially the family thought the behaviour was cute.
Fiona Gibbs and her dog Leo from Pymble. Leo is one of four dogs that have been treated for dementia with a stem-cell transplant. Credit: James Brickwood
Then Leo "became scarily aggressive" and didn't recognise Mrs Gibbs or the family's five children.
"At one stage, we were almost defending ourselves with brooms. He was like a rabid dog," she said.
Now, three years later, Leo, a Pomapoo (a mix of pomeranian and poodle), is back to his normal placid self after a stem cell transplant appears to have reversed his canine cognitive dysfunction or dementia. This success is giving researchers hope of finding a cure for human dementia.
Research estimates that 12 per cent of dogs older than eight years have dementia, rising to a third of dogs older than 14 years. In many cases, dog owners think signs like the dog staring at a wall is normal ageing. It is not.
Leo's transplant was performed as part of a Dogs and Cells program at University of Sydney headed by Michael Valenzuela, a professor of regenerative medicine who specialises in dementia and Alzheimer's in humans (and dogs).
Professor Valenzuela's interest in canine dementia was prompted when his own dog's vet told him about canine dementia. That's led to a 12-year research program of diagnosis, memory testing, brain banking, MRI and stem cell therapy, all in dogs.
"My great hope of course is that we can find a new way of eradicating dementia in our patients, both canine and human," he said. Like humans, dementia in dogs is characterised by a build-up of cerebral proteins known as amyloid plaques, linked to the death of brain cells.
University of Sydney is believed to be the only group in the world treating canine dementia with stem cells.
Over the past 10 years, it has treated four older dogs, which had tested positive for canine dementia. It successfully reversed dementia in two, Leo and Timmy, a Wollongong dog that died of old age last year. Another dog died from surgical complications, and the fourth didn't respond.
The "spectacular outcomes" with Leo and Timmy are the "only cases" in the world that Professor Valenzuela knows of which have resulted in the "reversal of a natural dementia-like condition in a higher order animal".
Ms Gibbs said Leo is now placid again.Credit: James Brickwood
He plans one more canine stem cell transplant before conducting randomised trials on dogs to compare varying cell doses. Within five years, he plans to launch a human clinical trial.
"I believe our approach is very promising and the only one with evidence in dogs who show so many parallels with human Alzheimer’s dementia," he said. "I’m therefore working hard to try to get our technology to human clinical trial."
The stem cell transplant is performed under anaesthetic. Vets take a small piece of skin from a dog's abdomen, harvest it and use it to grow neural cells. A few weeks later the cells are injected into the part of the brain responsible for memory.
Ms Gibbs was initially sceptical about the procedure. But now Leo is placid again. "You don't need to be scared of him," she said."If I had dementia, I would want it."
Professor Valenzuela will appear on a free panel at 6pm on Wednesday June 27 at University of Sydney to discuss whether dogs benefit humans as friends and whether owning a dog can lead to better health.
Signs of doggy dementia
Staring at the wall.
Not recognising you when you come home.
Not finding dropped food.
Getting stuck behind furniture at home.