If you’ve ever felt like your dog was really happy to see you — maybe even misty-eyed — it turns out you’re not just imagining things. A 2022 study from Japan suggests that dogs produce happy tears when reunited with their favorite humans, adding to growing evidence that our canine companions may feel joy in ways even closer to ours than we thought.
Tears of Joy (Literally)
Researchers from Azabu University found that dogs produce more tears when greeting their owners than when they greet familiar acquaintances. The study, published in Current Biology, measured tear production in dogs after reunions with both their owners and known but less-familiar people. The results? Dogs were significantly more teary-eyed when they saw their favorite humans.
These weren’t full-on waterfalls, but their eyes did well up — especially five to seven minutes into the reunion. According to the study’s lead author, Takefumi Kikusui, this is the first scientific evidence of emotionally triggered tears in non-human animals.
It’s All About the Love Hormone
So what’s behind the waterworks? Oxytocin — also known as the “love hormone.” This chemical surges in both dogs and humans during moments of bonding. It’s the same hormone released when a dog sees their owner, gets cuddles, or, in Jasmine the standard poodle’s case, nurses her puppies. Kikusui first noticed her teary eyes during nursing and got curious.
To test the link, researchers applied oxytocin eye drops to dogs and saw a significant increase in tear production — but not when they applied a control solution. In short: more oxytocin = more puppy tears.
Are They Really That Happy?
According to other experts, maybe. Psychologist Ad Vingerhoets, who literally wrote the book on why humans cry, says the study’s focus on tears of joy— not distress — makes it especially compelling. Emotional tears are often associated with sadness, so finding evidence of happy tears in dogs could reveal a new layer of their emotional depth.
Plus, another experiment in the study showed that people rated teary-eyed dogs as cuter and more nurturing, suggesting that dogs may have developed this tear response as a subtle social signal — one that tugs on our heartstrings and maybe even earns them extra belly rubs.
Do Dogs Cry Like We Do?
Not exactly — at least not yet. Some scientists argue that dogs’ tears might be more of a physical reaction than an emotional one, possibly a trait humans accidentally bred into them over thousands of years. After all, we’re hardwired to care for teary eyes and expressive faces. Still, it’s possible we’re watching evolution in action — a behavior that began as a reflex becoming something more emotional over time.
“They coevolved with humans,” said Asmir Gračanin, a psychologist at the University of Rijeka in Croatia who was not involved in the work. “If I would have to choose among all different species of mammals, I would definitely look into dog’s behavior to look for if there is some kind of special communication [with humans].” He goes on to say that dogs may only cry for their owner, over other environmental triggers.
Final Thoughts
Whether it’s emotion or evolution (or both), one thing’s for sure: dogs feel deeply. So the next time your pup runs to you with watery eyes after a long day apart, you might just be witnessing a very happy reunion — with tears to prove it.
Turns out, man’s best friend might also be man’s most sentimental.
