Roll over — and delay death?

Turns out, one of the many tricks that dogs can do for their humans is to help them live longer — especially if they live alone, or have previously suffered a heart attack or stroke, according to the American Heart Association.

The tail-wagging findings come from a meta-analysis of almost 70 years of global research published in the journal “Circulation” on Tuesday, as well as a new Swedish study of heart attack and stroke survivors spanning over a decade.

The first meta-analysis drew on data from almost 4 million people in the U.S., the U.K., Canada, New Zealand, Australia and Scandinavia, and associated dog ownership with a 24% decreased risk of dying by any cause, and a 64% reduced risk of death after a heart attack in particular. In fact, if the dog owner had experienced a heart attack or stroke, then that person saw a 31% decreased risk of death, compared to the cardiovascular event survivors without a dog.

“Having a dog was associated with increased physical exercise, lower blood pressure levels and better cholesterol profile in previous reports,” wrote Dr. Caroline Kramer, assistant professor of Medicine at the University of Toronto and an endocrinologist at Mount Sinai Hospital. Those are all keys to a healthy heart.

This news comes on the heels of a separate study of more than 336,000 Swedish dog owners and non-owners who had suffered a heart attack or stroke, which was also published Tuesday. And it found that the risk of death for heart attack patients who lived alone — but had dogs — was 33% lower than the solitary adults without dogs. And stroke patients living alone with pups had a 27% lower risk of death compared to those without dogs.

Related:Nearly half of Americans report feeling alone

Now, dog owners who lived with a partner or child also survived longer after a heart attack (seeing a 15% reduced death risk) or stroke (a 12% reduced death risk) compared to patients without dogs, but pet ownership appears to especially benefit those who live alone.

Both reports credit the increase in physical activity that keeping a dog entails — such as taking them on daily walks and playing with them — as research shows that exercise strengthens the heart and promotes overall health. Indeed, a recent Mayo Clinic study of 1,800 people found that those with canine companions were more likely to practice heart-healthy lifestyle habits such as exercising, eating well and having ideal blood sugar levels compared to those without a dog.

And researchers in the new studies noted that caring for a fur baby also decreases loneliness and depression, which can account for the added longevity among more isolated adults. Last fall, the National Poll on Healthy Aging surveyed more than 2,000 adults aged 50 to 80. More than half owned a pet, and 79% of the senior pet parents said that their animal companions reduced stress. And among those who lived alone and/or reported fair or poor physical health, 72% said their pets helped them cope with physical or emotional symptoms.

Related:6 reasons seniors should consider getting a pet

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

Of course, the researchers also reminded the public that taking on a pet is a big responsibility not to be undertaken lightly or as an instant cure-all.

Indeed, they’re physically demanding — which can be good for being more active, but can also pose a hazard for someone recovering from a medical procedure. A recent JAMA study reported that bone fractures related to seniors walking their dogs more than doubled between 2004 and 2017. And 6% of seniors in the National Poll on Healthy Aging reported that their pets caused them to fall or otherwise injure themselves. So patients should consider their physical limitations before adopting a pet that needs a lot of activity.

And it takes a lot of scratch to care for a dog or a cat. Rover.com reports that canines cost their owners $153 a month on average, adding up to $1,836 a year. The American Society for the Prevention of Cruelty to Animals (ASPCA) puts the average annual cost of care at $875 for a large dog, $670 for a cat, $200 for a small bird and $35 for a fish (not including the cost of setting up an aquarium.)

Related:Americans are willing to wreck their financial futures on behalf of their pets