UC Davis professor explores stem cell therapy on dogs
Rick Vulliet, DVM, PhD, a professor at the UC Davis School of Veterinary Medicine, is leading a study to determine the effectiveness of autologous stem cell therapy on dogs with degenerative myelopathy and dilated cardiomyopathy.
In an effort to try to treat these incurable diseases, Vulliet’s research ventures into the near-science-fiction realm of stem cell therapy. A self-proclaimed “agnostic” on the topic of stem cells, Vulliet has high hopes for the technology, but maintains a degree of skepticism.
He noted the large number of claims in the media regarding the apparent miracle cure that stem cells offer.
“If you read CNN[.com], you get a shot of stem cells and everything is OK,” he said. “Most of the claims are generally bogus.”
He said he chose to focus on degenerative myelopathy and dilated cardiomyopathy because they both occur in older dogs and they are both terminal. Degenerative myelopathy especially is heartbreaking to pet owners, since they are forced to watch as their companion slowly loses mobility.
“There really is nothing in classical veterinary medicine that can treat this disease,” Vulliet said.
Harvesting hope for dogs
Vulliet has just begun to recruit dogs with dilated cardiomyopathy, but he has already begun clinical treatment of several degenerative myelopathy patients.
To treat these dogs, Vulliet extracts adult bone marrow cells – mesenchymal stromal cells (MSCs) – from the patient under anesthesia. The cells are then put in a tissue culture dish for about three weeks, under conditions in which only the stem cells will grow. He then collects the cells and re-injects them into the dog intravenously.
Vulliet said he expects the stem cells to travel into the lungs, where they should stay for a week or so. He hopes the cells will then migrate from the lungs and begin to treat the disease.
“The most likely outcome is the stem cells will go into the spinal cord and stabilize the disease,” he said. “It no longer gets any worse but it doesn’t get better.”
This result would be the key to treating dogs that are diagnosed early. However, the stem cells could also reverse the disease, make it worse, or have no effect, he said. The truth is that nobody knows what will happen.
“Even if we establish that they work, it will take us a long time to figure out how they work,” he said. “This is a 20-year problem.”
Vulliet worked with 30 laboratory dogs to practice the bone marrow extraction and cell-growing techniques, but so far only a few dogs have been treated clinically for degenerative myelopathy, and it is too soon for any conclusive results.
“It will be six months to a year to determine if they’re effective or not,” Vulliet said. “We’re not in a position to evaluate it yet.”
If the treatment is viable and approved, veterinarians should be able to do the majority of the treatment in their own practices. Extracting the marrow and re-injecting the cells is a simple procedure, he said, but the cells would need to be grown in a lab.
“Any veterinary practice near a tissue culture facility could use this technique,” he said.
The study is funded mainly by the American Kennel Club Canine Health Foundation. Degenerative myelopathy mostly affects German shepherds, and Doberman pinschers are common victims of dilated cardiomyopathy.
Cats benefit, too
Vulliet is also studying the efficacy of bone marrow stem cell treatment on lipoprotein lipase (LPL)-deficient cats. He said the research in cats has been more successful so far, because the results are more clear-cut.
Lipoprotein lipase-deficient cats lack the ability to metabolize chylomicrons – lipoprotein particles that transport fats from the intestines to other parts of the body. Evidence for LPL deficiency is in the blood serum.
“Usually the color of a lager, [the serum] in this case is milky white,” Vulliet said. “When we put the stem cells into them it will actually clear up for a while.”
In the case of the dogs being treated for degenerative myelopathy, the results are not so obvious.
“I squirt in the stem cells, and maybe the dog has a good week next week. Is that because of my stem cells? No, it’s because the disease goes up and down,” he said. “You’ve got a dog with degenerative myelopathy, and the end point is not as clearly defined. These cats are very easy to quantitate.”
Despite his success with the cats, the procedure is not perfected. After three or four months the condition returns, and their serum becomes milky again.
“There are more unknowns than there are knowns right now,” he said.