Researcher Says Dog Will Cry Haru When Meeting Again With Human He Knows

JAKARTA - Dog's eyes turned out to be more teary when they met human beings whom they knew than humans, said a new study in the journal Current Biology.

"We found dogs shed tears related to positive emotions. We also made the discovery of oxytocin as a mechanism that might underlie it," said Takefumi Kikusui of Azabu University, Japan as quoted by ANTARA from Science Daily, Friday, September 2.

Kikusui and his partner found this after one of the two considerings gave birth 6 years ago. He noticed when his dog was breastfeeding, there were tears. The tears don't fall as often happened to humans but they make their eyes teary.

"It gives me the idea of oxytocin can increase tears," said Kikusui.

Oxytocin is known as the mother's hormone or the love hormone. According to research, oxytocin is released in dogs and their owners during their interaction. So, the researchers decided to carry out a reunification experiment and see if it made the dog cry.

First, they used standard tests to measure the volume of dog tears before and after meeting their owners again. They found that the volume of tears rose when the dogs returned together with the humans they knew. When the Kiasui and the team added oxytocin to the dog's eyes, their tear volume also increased.

The findings support the idea of releasing oxytocin play a role in the production of tears when dogs and their owners return together. Kikusui asked people to assess pictures of dog faces with and without tears.

As a result, they gave a more positive response when they saw dogs with teary eyes. These findings show the production of dog tears helping to establish a stronger relationship between the owner and their dog.

According to researchers, it appears that dogs shed tears in a situation that is considered happy by humans. However, they have not tested whether dogs also shed tears in response to negative emotions.

They also don't know if dogs shed their tears when they met other dogs again.

"The dog has become a human partner, and we can form a bond. In this process, it is possible that dogs show teary eyes when interacting with their owners will be further cared for by their owners," said Kikusui.