Japanese Scientists Uncover Surprising Discovery About Dogs’ Emotional Bond With Humans

Chisom Ndianefo
Unsplash | Alvan Nee

It's not a hidden fact that dogs are some of the most emotional animals out there. They're sensitive and always find ways to express whatever emotions are running through their minds. Scientists reveal exciting facts about these furry friends often, and just when you think you've seen it all, your mind gets blown all over again.

Keep reading for the details.

Teary Eyes

Unsplash | Karl Anderson

A new study from Japanese scientists reveals that your dog's eyes may get filled with happy tears when they see you after a long time apart. These tears foster the bond between a dog and its human as it has been thousands of years before now.

Yes, Dogs Have Ducts


Are you surprised at this discovery? Dogs have functioning tear ducts that release tears frequently to help keep the eyes clean. The only difference between your tear ducts and dogs is that those tears don't fall like yours and have not been linked to any emotions before this recent study.

Takefumi Kikusui Led The Mission

Unsplash | Kieran White

Takefumi Kikusui, a professor at the Human-Animal Interaction and Reciprocity Laboratory at Azabu University, Japan, took it upon himself to dig deeper into the mystery of dog tears after she noticed a few from his poodle six years ago as he nursed her puppies.

Dog Tears Are Linked To Positive Emotions

The study stated the dogs shed tears to convey positive emotions in the Current Biology Journal she co-authored.

“We found that dogs shed tears associated with positive emotions."

Oxytocin May Be A Major Factor

Unsplash | Alvan Nee

The team also revealed that oxytocin might be a likely factor responsible for the release of the tears. Oxytocin is a hormone in humans associated with empathy, trust, and love. It's sometimes called the love or maternal hormone.

Running The Test

To identify the link between dog tears and reuniting with their owners. Kikusui and his team calculated the amount of tears released by 18 dogs with the help of a procedure known as the Schirmer Tear Test.

The Schirmer Tear Test


This procedure is carried out by placing a paper strip inside the eyelids of the dogs for about 60 seconds before and after they reunite with their humans after about five to seven hours of separation between them.

Comparing Before And After

Dog playing with a ball.
Flickr | gretchencaldwell429

The researchers then finalized their test by comparing the amount of tears released before and after meeting with their owners and familiar faces. One result was very accurate, and it's that the tears increased after the reunion process.

The Role Of Oxytocin

This hormone was applied manually to the surface of 22 dogs' eyes via a solution. The tears produced increased significantly after the oxytocin application compared to that of the control solution.

Dogs' Reactions To Negative Emotions

While we now know that your dog may cry due to a sweet moment of reunion, it's however not been established if they use tears to respond to a negative emotion too as humans do.

Tears & The Canine Sphere

Unsplash | Ash

The test didn't also prove any connection between a dog's ability to produce tears and social interaction in the canine world. Perhaps this is because the animals haven't found a reason why the tears come out.

Humans May Respond Better To Teary-Eyed Dogs

Kikusui revealed a chance that humans would pay better and closer attention to dogs that cry often. She stated that dogs have now become good partners for people and forming a bond is very feasible.

Ranking Dogs With Or Without Tears

Flickr | ND Wind Twins

The team showed 74 people images of dogs with and without tears, telling them to rank these dogs. Results proved that people showed more empathy and positive emotions to the dogs with tears in their eyes.

A Bit Of Skepticism

Jessica Meekins who is an associate professor of veterinary ophthalmology at Kansas State University isn't fully convinced by this finding as she states that tears production fluctuates in humans and animals hence measuring them doesn't exactly prove anything.

Filed Under: