The researchers reported that dog owners who lived alone were 11 percent less likely to die of heart disease and a third less likely to die from any cause, compared with those who lived alone and didn't have a dog.
Scientists said the companionship was key, along with the physical activity in taking the dog for a walk.
The team from Uppsala University in Sweden analysed data from 3.4 million Swedes aged 40 to 80 by combing through a national database of hospital visit records and dog ownership registrations. So, is owning a dog connected to better health?
Your dog could be literally saving your life. It's possible that people who choose to own dogs may simply be more active and in better health to begin with, say the authors.
Fall also adds that there may be slight differences between dog owners and non-owners well before any of the two groups were exposed to dogs, which could have influenced the results.
The researchers found that, in age and sex-adjusted analysis, dog ownership was inversely associated with risk of heart attack, ischemic stroke, heart failure and composite CVD, as well as cardiovascular mortality and all-cause mortality.
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A malnourished Yemeni child receives treatment at a hospital in the port city of Hodeida on November 05, 2017. Humanitarian flights could still come in and out using a visual approach.
That includes dogs like golden retrievers, labrador retrievers and pointers. According to Tove Fall, senior author of the study and associate professor in epidemiology at the Department of Medical Sciences and the Science for Life Laboratory, Uppsala University, there are other explanations, including that having a dog typically means increased well-being and social contacts for the owner in addition to effects of the dog on their bacterial microbiome.
Dr Mubanga said: "Perhaps a dog may stand in as an important family member in the single households".
The results? Dog owners - especially dog owners who lived alone - had a lower risk of dying from cardiovascular disease.
"However, as many dog owners may agree, the main reason for owning a dog is the sheer joy".
Instead, dog owners may just be healthier to begin with.
While some previous studies have shown similar positive effects for pet ownership generally, others have shown the opposite effect.