Dogs also “cry” with joy

A new study, which could be the first to look at this question, has found that dogs also “cry” when they have happy emotions, especially when they are reunited with their owners, according to the researchers published in the journal ‘Current Biology’.

“We discovered that dogs shed tears associated with positive emotions,” explains Takefumi Kikusui of Azabu University, Japan. “We also made the discovery of oxytocin as a possible underlying mechanism.”

Kikusui and his colleagues made the discovery after one of his two poodles gave birth to puppies 6 years ago. They realized that when their bitch suckled the puppies, something changed in the face of the animal and there were tears. Those tears do not fall as they usually do in humans, but they do fill their eyes with tears. “That gave me the idea that oxytocin might increase tears,” says Kikusui.

Oxytocin, he explains, is known as the maternal or “love” hormone. The researchers also knew from previous observations that oxytocin is released in both dogs and their owners during interactions. So they decided to conduct a reunification experiment and see if it made the dogs cry.

First, they used a standard test to measure the Tear volume of dogs before and after meeting with their owners. They found that, indeed, the volume of tears increased when they met with the known human and not with a person they did not know.

When they added oxytocin to the dogs’ eyes, their tear volume also increased. This finding supports the idea that oxytocin release plays a role in tear production when dogs and conspecifics are brought back together.

They also asked people to rate photos of dogs’ faces with and without artificial tears, and it turned out that people gave more positive responses when they saw dogs with teary eyes. These results suggest that dogs’ tear production helps forge stronger connections between people and their dogs.

Kikusui claims the findings were a surprise. “We had never heard of the discovery that animals shed tears in joyful situations, such as reunions with their owners, and we were all excited that this was a world first,” he notes.

In this case, it appears that dogs produce tears in situations that humans would consider “happy.” They have not yet tested whether dogs also produce tears in response to negative emotions. They also don’t yet know if dogs produce tears when they hang out with other dogs. They are waiting to see if this response also has a social function in the canine world, but for now they say it seems to have clear implications for the dog-human bond.

“Dogs have become companions to humans, and we can form bonds,” Kikusui says. In this process, it is possible that dogs that show watery eyes during interaction with the owner are more cared for by the owner.”

Source-listindiario.com