Science has finally caught up with what dog lovers have known for years--that having a dog is great for your health. Here are six ways science has proven that living with a dog promotes better heart health.

Decreased cholesterol and triglycerides. Lower cholesterol and triglycerides reduces the risk of cardiovascular disease. Results of a three-year study of over 5,700 people showed that those who lived with pets, including dogs, had lower blood pressure and triglyceride and cholesterol levels than did non-pet-owners, even after accounting for additional exercise, smoking, diet, weight, and socioeconomic profile.

Lowered blood pressure. Women undergoing stress tests have lower blood pressure in the presence of dog than they have in the presence of a friend. The simple act of petting your dog causes your blood pressure to drop. What's more, the lowered blood pressure stays in effect even when the dog is no longer present.

Improved chance of surviving a heart attack. A study conducted by the US Department of Health concluded that 28% of heart patients with pets, including dogs, survived serious heart attacks, compared with only 6% of patients who did not have a pet, even after accounting for factors such as the severity of heart disease.

Longer life-expectancy after a heart attack. A study published in the American Journal of Cardiology found that men who had a dog were six times more likely to be alive one year after a heart attack than men without a dog. The presence of a pet affected survival rate even more than having a spouse or friends.

Reduced stress. A study by State University of New York at Buffalo of stockbrokers who had dogs or cats in their offices had smaller increases in blood pressure when they had to carry out stressful tasks than those who did not have a pet present.

Increased exercise. One study showed that when people get a dog, they increase their walking time fivefold--from an average of one hour to five hours. Five hours of walking per week has a benefit equal to giving up smoking.

So, the secret to a healthy heart may be trading in that hotdog for a hot-looking Dachshund--or Great Dane or Boxer.