Dog owners live longer and have healthier hearts, a new study from the University of Toronto shows.

"Dog ownership is associated with increased physical activity levels and increased social support, both of which could improve the outcome after a major cardiovascular event," the study said. "Dog ownership may be particularly important in single-occupancy households where ownership provides substitutive companionship and motivation for physical activity."

The research was vast, analyzing 4 million people across six countries, and found that dog owners had a lower risk of dying early by 24 percent. It also revealed those who already had a heart attack reduced their risk of dying by 31 percent by owning a dog. 

Researchers believe part of these health benefits could be from consistent exercise from owning a dog and the ability to identify physical ailments earlier because of the increased exercise. 

Dog ownership has previously been linked with alleviating social isolation, depression and loneliness.