Dogs could be offering clues to how Alzheimer's disease develops in humans.
Dog dementia is often seen as comparable to Alzheimer's in humans.
Past studies have shown it affects between 14% to 35% of older dogs.
A recent study from the Dog Aging Project found the disease is more than six times higher in dogs that aren't active.
"The exercise factor was really important because it's modifiable," said Annette Fitzpatrick of the University of Washington. "Things like age... genetics are not modifiable, but something like exercise is something that we can change."
Other risk factors in dogs include neurological disorders and vision and hearing issues.
Fitzpatrick says those are similar risk factors for people with Alzheimer's.
"For dementia, prevention is really the best thing to do," she said. "Stay active, be social, keep your brain working, do crossword puzzles, and for dogs, we might not be able to do as much, but just the awareness of things like social activity."