We have known for years that owning a dog or cat is associated with lower stress and blood pressure. But new research suggests that having a pet can prevent cognitive decline as you get older. Researchers at the University of Michigan collected cognitive data from over 1,300 older adults with normal cognitive skills. The participants were given multiple cognitive tests over the next six years so that the researchers could develop a cognitive score for each person. They found that cognitive scores decreased at a slower rate in pet owners. The protection against brain and cognitive decline was greatest for those who had a pet for a long period of time.