Yes, Your Dog Sheds Tears of Joy When It Sees You

Upon reuniting with its owner, a dog will bark, wag its tail, and run around in circles. But did you know that it will also shed tears of joy?

That’s how much canines love their humans. According to a recent study by Martha Stewart.com, research has shown that dogs shed tears to keep their eyes clean, but they’re also expressing positive emotions after being separated from their owners during a long period.

Takefumi Kikusui, a professor at Azabu University in Japan, decided to look into the matter after seeing his poodle get teary-eyed as she nursed her puppies some six years ago.

“We had never heard of the discovery that animals shed tears in joyful situations, such as reuniting with their owners, and we were all excited that this would be a world first,” said Kikusui.

To test out the theory, the researchers observed the responses of 20 dogs after a reunion with their owners and around acquaintances. The volume of tears produced revealed that canines became more misty-eyed with the former but not so much with the latter.

To see if the tears were linked to emotion, the study used a solution containing oxytocin, a hormone associated with love. The researchers applied it to the dogs’ eyes and found it increased tear volume.

Interestingly, the study also found that canines put on their adorable puppy dog eyes to receive attention from humans. In another test, 74 people were asked to rate dog photos, which resulted in teary-eyed participants and less emotional reactions. The participants’ results revealed that they had shown more empathy toward those dogs in tears.

“Dogs have become a partner of humans,” Kikusui added, “and we can form bonds.”