Everyone knows dogs are man’s best friend, but they may also be one of our best hopes for treating age-related illnesses. Dogs develop many of the same diseases we do, including dementia, and their brains are structurally and functionally similar to ours. The Dog Aging Project aims to unlock insights that could extend healthier lives for both species.
Founded in 2014 by biologist Matt Kaeberlein and others, the Dog Aging Project is a large collaboration of dog owners, scientists, and veterinarians. It has enrolled more than 50,000 dogs at hundreds of veterinary clinics and hospitals across the country. Researchers collect detailed data on diet, exercise, blood biomarkers, and brain imaging, creating a public database accessible to scientists worldwide.
Kaeberlein says the biology of aging is highly conserved across animals, and some interventions that slow aging in laboratory species may work in dogs as well. Dogs offer a practical intermediate between laboratory mice and humans: they share our environment, eat similar food, exercise with us, and age much faster, giving researchers decades’ worth of information in only five to ten years.
Veterinary neurologist Stephanie McGrath helps track how canine cognition changes with age. Dogs in the project undergo cognitive testing — for example, memory tasks where a treat is hidden and the dog must recall its location. Owners like Pat Schultz enrolled dogs such as Murphy, a 12-year-old German shepherd–poodle mix, partly because of personal experience with human dementia: Schultz’s husband Bill had Alzheimer’s disease, and Murphy had been a constant companion. Tests showed Murphy becoming more anxious and facing increasing difficulties with memory tasks, signs consistent with cognitive decline.
All collected data feed research that has already produced findings linking lifestyle and environment to disease risk. One study found dogs living with other dogs had fewer diseases. Another showed dogs that did not exercise had a sixfold greater risk of developing cognitive decline.
When enrolled dogs die, many are donated for neuropathological study. Dr. Dirk Keene, a neuropathologist at the University of Washington, has long studied human brains for Alzheimer’s research and now examines dog brains from the project. He emphasizes the strong anatomical similarities: dog brains have frontal, temporal, and occipital lobes like human brains, and dementia produces comparable patterns of shrinkage and enlarged brain cavities. Under the microscope, donated dog brains can show hallmark Alzheimer’s features such as beta-amyloid plaques, appearing strikingly similar to those in humans.
One promising avenue being tested is rapamycin, a drug that in mice has slowed cognitive decline and extended lifespan dramatically. A pilot study of 12 dogs with signs of dementia compared placebo versus rapamycin. Molecular biologist Julie Moreno examined brains after some treated dogs died and found fewer microglial cells — immune cells associated with neuroinflammation — in dogs that had received rapamycin, suggesting reduced inflammation linked to dementia. These early results were encouraging enough to prompt a larger, NIH-funded clinical trial giving hundreds of dogs either rapamycin or a placebo to see if the drug can safely extend healthy life.
Alongside academic research, for-profit companies are developing interventions aimed at delaying age-related decline in dogs. Loyal, a biotech founded in 2019 by Celine Halioua, is developing drugs intended to be given preventatively, similar to a daily statin, to keep dogs healthier longer. Halioua describes the goal as adding roughly one healthier year of life, though actual benefit could vary. One of Loyal’s drugs is in clinical trials for dogs over age 10; the FDA has reviewed safety data and noted a “Reasonable Expectation of Effectiveness,” though final results will take years. Silicon Valley has invested heavily in canine longevity startups, viewing dogs as a faster path to understanding aging biology that could eventually inform human therapies.
For owners like Schultz, participation is both personal and pragmatic. Her husband died from Alzheimer’s complications two years ago, and she continues to focus on ensuring Murphy ages as comfortably as possible. She observes parallels in care: both humans with dementia and aging dogs benefit from love, reassurance, and steady routines that reduce anxiety.
The Dog Aging Project’s combination of large-scale observational data, tissue donation, and controlled clinical trials aims to accelerate discoveries about how to prevent or slow age-related diseases. By studying naturally occurring aging and disease in a species that shares our environment and exhibits comparable pathology, researchers hope not only to improve the health span of dogs but also to translate findings that could help people live longer, healthier lives.