Dogs and health: A lower risk for heart disease-related death?

Robert H. Shmerling, MD

Senior Faculty Editor, Harvard Health Publishing

Are you a “dog person”? You know, one of those people who talks about their dogs all the time, shares photo after photo online (or, worse, in person), and considers their dog as a semi-human member of the family? (In the interest of full disclosure, I am a dog person.)

If you are, here’s a medical news story that may confirm what you’ve suspected all along. And if you aren’t a dog person, this may confirm your suspicion that researchers can prove just about anything they want. According to a recent study, your risk of having a cardiovascular event such as stroke or heart attack, and your risk of death, are lower if you have a dog. Some of the proposed explanations for this might surprise you.

Research finds a new connection between dogs and health

This new study reviewed the health and death records of more than 3 million people in Sweden ages 40 to 80 over more than a decade, and found that:

  • Compared with people in multi-person households without dogs, people living in multi-person households with dogs had a risk of death that was 11% lower, and risk of death due to a cardiovascular cause that was 15% lower.
  • These findings were even more dramatic for those living alone. Risk of death was 33% lower among dog owners, cardiovascular deaths were lower by 36%, and the risk of heart attack was 11% lower.
  • The benefit was greater for owners of certain breeds of dogs, such as retrievers and terriers.

Why might dog ownership come with health benefits?

The most obvious explanation for why dogs might provide their owners with certain health advantages is that dog owners tend to be more active. For many people, taking their dogs out of the house or apartment several times a day to “do their business” and walking their dogs is far more physical activity than their dogless neighbors. And this could explain why more active dog breeds (such as retrievers) are associated with the greatest benefit, and why single people (who must shoulder all of the “burden” of walking the dog) benefit the most.

But there are other potential explanations that researchers have considered, including:

  • Improved immune function. Believe it or not, having a dog that brings dirt and germs into the home could improve how the immune system functions and reduce harmful inflammation in the body.
  • Modifying the microbiome. The huge number of bacteria in our digestive tracts changes not only with changes in diet, but also with pet ownership. It’s possible that having a dog alters the types of bacteria we harbor, which in turn could affect inflammation in the body and resultant cardiovascular risk.
  • Social impact. Dog owners must, to at least some degree, focus outside themselves, which can promote social interaction. In addition, dog owners tend to bond with one another as their dogs play together and check each other out. Past research has found that social contact is linked with lower cardiovascular risk and rates of death.
  • Improved mood. Some have proposed that the unconditional affection and companionship of dogs can improve mood, and through this effect improve health.

Will getting a dog extend your life?

Not so fast. This study only found that dog owners tend to live longer and have fewer heart attacks than those without dogs. But that does not prove dog ownership itself it the reason. Maybe healthier, more active people get dogs more often than sedentary people, and it’s that self-selection that accounts for the observations of this latest research. It’s also possible that economic factors play an important role. Dog ownership can be expensive, and those who can most afford to own a dog might receive better healthcare, have better health insurance, or have healthier lifestyles. While the researchers tried to account for some of these possibilities, excluding some contribution from other “non-dog” factors is challenging.

We’ll need to have a better understanding of whether dog ownership itself truly provides health benefits and just how it works. Naturally, similar questions will arise regarding cats and other pets. Until we know more, the apparent health benefits of dog ownership should be encouraging to dog people everywhere. And if you aren’t a dog person, this latest research might convince you to become one.

Follow me on Twitter @RobShmerling


  1. G. Raysman

    To Ms. Butner: Poodles! hypo-allergenic, non-shedding and smart!

  2. della biggers

    For people with allergies to pet dander, there are breeds that do not shed hair or dander. One example is a Schnauzer. I have a Miniature Schnauzer and he is an old man now. He has been a wonderful pet; very playful, loyal and loving.

  3. Merlin

    What about cat owners? They follow you like a dog and can fetch a
    thrown ball. I think they are really intelligent and understand
    when spoken to. Their constant purring can lower anyone’s blood
    pressure. Let’s hear it for the cats!!!

  4. Elza C. Butner

    What would you recommend for people with allergies to dog dander, yet who would like the benefits of having a dog (and love dogs!). For some the suffering from the allergies to dogs is so great (asthma, rash, itching, sneezing) that living with one would be very difficult. Is there hope for such individuals?

  5. azure

    I’d like to see more people who get dogs appear to have a better understanding of the needs of the dog as well as the need to do basic obedience training with or of their dog (if they can’t do it, hire a trainer!). Too many people (at least where I live) get dogs, then don’t exercise them enough, even if they’ve gotten a mix or breed of dog that clearly requires (if a specific breed is known to need) substantial exercise and/or socialization. Yet not be willing or able to pay a dog walker or for dog day care.

    If you are unable tor unwilling to do more then a walk around the block 2 times/day & don’t have alot of space for the dog to run (and be out there to toss balls or whatever to make sure the dog does run/exercise–every day), get a dog that is temperamentally & physically satisfied by a low activity level. If you’re not interested in dealing w/a frequently barking dog (usually barking at nothing or people passing by or your neighbor spending time on his/her property within view of the dog) either provide your dog with information/training regarding when barking is ok, when it is not, or get a breed that rarely barks.

    Bored/poorly/untrained/inadequately exercised dogs often bark at anything, whether it’s a neighbor spending time in their yard (and the dog’s seen the neighbor 30 times before), people walking by, a large vehicle, a squirrel . . . . and keep barking. It’s really annoying. In some rentals, it’s enough to eventually get you & your dog evicted. It’s pretty selfish behavior to “improve” your health by getting a dog, while increasing all of your neighbors’ stress levels because you can’t be bothered to adequately exercise or train your dog.

    Plus, a well trained dog is a wonderful companion; the training process deepens one’s friendship & partnership w/one’s dog or any dog you spend some time with–that has been my experience. If something happens to you or for some reason you cannot keep your dog, a well trained dog is far more adoptable & likely to be kept by the new owner(s)/family then one that is not. If you care about your dog (and your neighbors) train it. Training a dog will improve your mental & physical health.

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