According to a study done by Swedish researchers, having a dog as part of the family was linked to a reduced risk of cardiovascular disease. In Sweden all dogs are tagged and registered. The study lasted 12 years and included 3.4 million Swedes ages 40 to 80. Owning a dog proved to have a 20 to 23% decrease in death by cardiovascular disease. The results proved to be higher with owners of larger, active breeds since these dogs encouraged the owner to get out more to exercise their pets. Lap dogs just kept the person warm.