American Heart Association news: Dogs boost cardiovascular and overall health

kuznetsov_konsta/stock.adobe.comYou and your veterinary clients know that dogs make your heart happy. Now, a new study and meta-analysis published in an American Heart Association journal show that dogs may have medical benefits: longer life and better outcomes following cardiovascular incidents.

In the study, the risk of death was lower following hospitalization among Swedish dog owners who suffered a heart attack or stroke than for patients who did not own a dog. Specifically, among those who lived alone and suffered a heart attack or stroke, dog owners were 33% and 27% less likley, respectively, to die during the study period. Of dog owners who also lived with a spouse or child, heart attack and stroke survivors were 15% and 12% less likely, respectively, to die during the study period.

Researchers used heart attack and stroke reports spanning more than a decade from about 150,000 people (5% of whom owned a dog) and 182,000 people (6% of whom were dog owners), respectively. Dog ownership was confirmed by data from the Swedish Board of Agriculture (registration of dog ownership has been mandatory since 2001) and the Swedish Kennel Club (all pedigree dogs have been registered since 1889).

The lower risk of death associated with dog ownership could be explained by increased physical activity and decreased depression and loneliness, both of which have been connected to dog ownership in previous studies, according to a release announcing the study.

“Previous studies have indicated that dog owners experience less social isolation and have more interaction with other people,” said Tove Fall, DVM, a professor at Uppsala University in Sweden. “Furthermore, keeping a dog is a good motivation for physical activity, which is an important factor in rehabilitation and mental health.”

For the meta-analysis, researchers looked at data from more than 3.8 million patients from 10 studies, nine of which included comparison of all-cause mortality outcomes for dog owners and non-owners, and four of which compared cardiovascular outcomes for dog owners and non-owners.

The researchers found that, compared with dog-less patients, dog owners experienced a:

• 24% reduced risk of all-cause mortality

• 65% reduced mortality risk after heart attack

• 31% reduced mortality risk due to cardiovascular-related issues.

Although the analyses did not take into account confounding variables such as better fitness or a healthier lifestyle that could be associated with dog ownership, the results were very positive. “Our findings suggest that having a dog is associated with longer life,” said researcher and endocrinologist Caroline Kramer, MD, PhD, an assistant professor at University of Toronto.

“The next step on this topic would be an interventional study to evaluate cardiovascular outcomes after adopting a dog and the social and psychological benefits of dog ownership. As a dog owner myself, I can say that adopting Romeo (the author's miniature Schnauzer) has increased my steps and physical activity each day, and he has filled my daily routine with joy and unconditional love.”

The findings don't prove causation between dog ownership and better health, but Glenn Levine, MD, chair of the writing group of the American Heart Association's scientific statement on pet ownership, says they're illuminating: “[T]hese two studies provide good, quality data indicating dog ownership is associated with reduced cardiac and all-cause mortality. While these nonrandomized studies cannot ‘prove' that adopting or owning a dog directly leads to reduced mortality, these robust findings are certainly at least suggestive of this.”

The study and meta-analysis were published in Circulation: Cardiovascular Quality and Outcomes. You can view the manuscripts of the studies here and here and read an editorial about the findings here.