By The Seattle TImes, adapted by Newsela staff
SEATTLE — When Daniel Promislow jogs with his 11-year-old Weimaraner, named Silver, it is hard for him to see the dog get old.
“Month by month, he gets slower and slower,” said Promislow, who studies genetics at the University of Washington (UW). His other dog, Frisbee, still frolics like a pup, but at 10, she also is considered elderly for a dog.
It’s a sad reality of pet ownership that our beloved companions never live as long as we would wish.
But Promislow and his colleagues think it might be possible to make pets live longer.
Using the latest in anti-aging research, the scientists plan to study a chemical that extends the life spans of mice, fruit flies and worms. They hope it will do the same for dogs.
“We’re not talking about doubling the healthy life spans of pets,” UW molecular biologist Matthew Kaeberlein said. “But at a minimum I would predict that you would get a 10 to 15 percent increase in average life span, and I think bigger effects are possible.”
There Is A Drug That Might Work
At a meeting in Seattle recently, experts from across the country brainstormed about the chemical rapamycin. They spoke about the best way to test its effects in pet dogs.
Rapamycin is currently used along with several other medications in organ-transplant patients. It keeps the body from rejecting their new kidneys, livers and other transplanted organs. The drug has also emerged as the most promising candidate among dozens of substances studied for anti-aging effects. Nearly 50 laboratory studies have shown that the drug can delay the onset of some diseases and restore vigor to elderly animals. It also extended their average life spans 9 to 40 percent.
No one knows if the drug might have similar effects in people. At the high doses used for organ transplants, rapamycin is associated with potentially serious side effects.
The low doses used in anti-aging research with mice and other lab animals cause few side effects. Large-scale human studies are costly and would take decades to complete.
But with dogs, it could be possible to find out in a few years whether rapamycin is beneficial.
“I think it’s worth a go, not just from what it can teach us about humans, but for the sake of the animals themselves,” said University of Alabama Biology Department Chairman Steven Austad, an expert on aging. “It may not work in dogs, but if it did, boy, it’s going to be huge.”
Figuring Out Why Some Dogs Age Better
Rapamycin works partly by shutting off a protein that promotes cell growth, Kaeberlein explained. As a result, cells grow more slowly, which slows the spread of cancer.
In elderly mice, it also improved the way the heart functions.
Effects on the heart are among the first things the researchers hope to track in dogs, Promislow said.
Some dog breeds, including Newfoundlands and Dobermans, are particularly high risk for heart failure, although cancer is the leading cause of death in most breeds. Large dogs generally have shorter life spans than the small breeds.
“We’re trying to understand why some dogs age better than others, and help all dogs age in a better way,” Promislow said.
The researchers plan to start as soon as possible with an initial study of 30 large, middle-aged dogs. They would be pets, not laboratory animals.
The animals would be monitored closely to see if the treatment causes any side effects. They’ll also be checked to see if the drug improves heart function or delays the start of heart problems or cancer.
The drug may not increase the length of the dogs’ lives. However, simply postponing disease could lengthen the period of healthy, active life they enjoy, Promislow pointed out.
Needed: More Pets To Sign Up
The researchers eventually hope to persuade hundreds of dog owners to enroll their pets in a much larger experiment. The goal would be to study the normal aging process of dogs, as well as to look at the long-term effects of rapamycin and how it works in dogs.
Government agencies like the National Institutes of Health, which focus on human disease, are not likely to fund it, Austad said.
So, the UW team is looking for unconventional sources of money.
Dog-food companies and animal organizations might be willing to contribute. Most of all, the scientists are pinning their hopes on fellow dog lovers.
“Given how I feel about my pets, I see this as a unique project where there’s a real potential for citizen science,” Kaeberlein said. “I think it would be great if pet owners who are really interested in improving the health of their animals would help fund this work.”
The researchers have set up a website where people can donate and sign up their dogs to possibly be included in the study. The website is dogagingproject.com.
Slow And Steady
The UW project sounds well-thought-out, said Dr. Jeffrey Halter, director of the University of Michigan Geriatrics Center. He cautioned that developing new drugs and treatments for both animals and humans is a long and difficult process.
A few years ago, the compound resveratrol — from grapes and red wine — was hailed as an anti-aging breakthrough. But follow-up studies have shown little effect.
“I think most of us who work in this field are not looking for an instant miracle,” Halter said.