Eudaimonia: Greek for the state or condition of good spirit, commonly translated as happiness or welfare.

The term “happiness” is used in the context of mental or emotional states, including positive or pleasant emotions ranging from contentment to intense joy. It is also used in the context of life satisfaction, well-being, and flourishing. Aristotle said that eudaimonia means “doing and living well.”

There are many things that can lead to happiness, cause happiness, or just remind us to be happy. This can include family members and loved ones, memories of events, a hobby or exercise, food, movies, vacations, or amusement parks.

Dogs have also been linked to happiness. In 2019, a study led by Lauren Powell, PhD, a postdoctoral researcher at University of Pennsylvania, looked at whether getting a dog improved the owner’s activity level, cardiovascular health, and psychological state.

Powell and her colleagues then compared the dog-owners to members of the two dogless control groups, statistically manipulating factors such as education, age, and appetite for exercise, to make sure that the canine alone accounted for any differences. After three months, people with dogs walked 2,589 more steps a day than the control groups.

“But at eight months there was a drop-off, so the difference was no longer significant,” said Powell, speculating that, “People were really excited at first, but maybe the novelty wore off.”

The psychological impact of a dog packed a bigger punch. They found that the loneliness in the group that got a dog decreased by 40 percent and stayed at that lower level at eight months. But how exactly do dogs make us happier?

In a previous study, Powell’s group had shown that owning a dog promotes the flow of oxytocin, a hormone that decreases our heart rate and fosters feelings of well-being and relaxation. Plus, she adds, dogs “encourage their owners to get out in nature, maintain a sense of routine, and stay in touch with their neighbors.”

Even on a neurochemical level, relationships with different sorts of animals have different effects on happiness. Paul Zak, an economist at Claremont Graduate University in California, has found in his research that dogs get a 57.2 percent oxytocin boost when they interact with their owners. Cats get a 12 percent boost. In other words, your dog truly adores you. Your cat accepts your presence … for now.

We derive happiness from many things. One of them is our dog, Louis. From my vantage point, Louis has achieved eudaimonia. He has constant companionship, sleeps in a comfortable bed, is treated with snacks, and even dresses in fancy clothes.

Louis’s state of eudaimonia helps with our happiness. Additionally, Louis has a back story. He was gifted to our family by one of my longest surviving patients who beat stage 4 lung cancer. She was diagnosed in 2002 with two large tumors in her brain and another large tumor in her chest. The median survival for this type and stage of cancer was eight months at the time. Miraculously, the chemotherapy and subsequent radiation therapy (after brain surgery and radiation) controlled her cancer for the better of 20+ years.

Being a lovable affectionate companion in addition to inspiring memories of my patient, Louis continues to bring us such joy and happiness — perhaps one day helping us, too, achieve true eudaimonia.