Can dogs really fall in love?

New Study Shows Dogs Release Oxytocin and Really Can Fall in Love

When people engage in an act of bonding – for example, hugging a loved one – our brains produce the neurochemical oxytocin, which is also known as the “love hormone.”

“I call oxytocin the ‘moral molecule’ because it motivates us to treat others with care and compassion,” wrote Paul J. Zak, a professor at Claremont Graduate University in California, in the Atlantic.

Zak and other researchers have performed dozens of studies over the past decade proving that humans release oxytocin when we are treated with kindness.


And now they have discovered something that probably seems obvious to most pet parents: Dogs (and other animals) also release the “love hormone” when they’re interacting with humans and animals.

A self-professed cat person, Zak was inspired to do the study after he became very emotional when he had to have his dog, Teddy, euthanized.

That animals of different species induce oxytocin release in each other suggests that they, like us, might be capable of love,” Zak wrote. “It is quite possible that Fido and Boots may feel the same way about you as you do about them. You can even call it love.”

In one experiment, blood samples were taken from a male goat and a male Terrier mix who liked to play together at an Arkansas animal sanctuary. After 15 minutes of chasing, play-fighting and romping around with the goat, the dog’s oxytocin level rose 48 percent.

“This shows that the dog was quite attached to the goat,” Zak wrote. “The moderate change in oxytocin suggests the dog viewed the goat as a ‘friend.’”

The goat, however, apparently saw the dog as much more than that — his oxytocin rose a whopping 210 percent.

“We essentially found that the goat might have been in love with the dog,” Zak wrote. “The only time I have seen such a surge in oxytocin in humans is when someone sees their loved one, is romantically attracted to someone or is shown an enormous kindness.”

(Dog/goat friendships aren’t all that uncommon; last year a German Shepherd and his goat BFF were reunited with their owner after they escaped from their yard in North Carolina.)

In another experiment conducted by Zak and the researchers, blood samples were drawn from 100 human participants before and after they played with a dog or cat for 15 minutes.

Surprisingly, the oxytocin levels increased in only 30 percent of the people.

“We found that one factor predicted whether playing with a dog would increase oxytocin: the lifetime number of pets of any type one had owned,” Zak wrote.

“If animals caused oxytocin release in humans, it would explain my surprise attachment to my dog Teddy, and perhaps why people spend thousands of dollars to treat a pet medically rather than euthanize it and simply get a new animal.

Interestingly, the opposite occurred for the participants who interacted with cats.

“Greater lifetime pet ownership caused oxytocin to fall linearly,” Zak wrote. “Dogs are simply more ‘people-oriented’ than cats, and previous pet ownership seems to have trained our brains to bond with them.”

The study also found that dogs lower people’s stress levels more than cats do.

“When stress hormones were lower, people in the experiment trusted strangers with more of their own money,” Zak wrote. “This may tell us why people who own dogs are judged as more trustworthy than those who don’t.

“The human-canine bond appears to be powerful and important to both species.”