While any kind of animal interaction is healthy, dog ownership can keep you more active.
A study from Michigan State University discovered that people who owned and walked their dogs were 34 percent more likely to meet the recommended 150 minutes of weekly physical activity. One reason is that dogs force you to walk more. A 2013 study found that dog owners/dog walkers spent nearly 50 percent more total walking time than two non-dog-walking groups. If you need to strengthen your social life, dog walkers have been found to converse more with people when out with their pet. And if you have suffered a heart attack, a dog may help you live longer.
A study by the National Institutes of Health examined 421 adults who suffered heart attacks and found that after a year, those who were dog owners were more likely to still be alive compared with non-dog owners, regardless of the severity of their heart attacks.
Source of information: https://www.uclahealth.org/Documents/Healthy-Years/HY_June2015.pdf