Dogs cry more when reunited with their ownersDate: August 22, 2022
Source: Cell Press
Summary: Dogs and humans clearly have a special bond. But do dogs, like humans, produce more tears at times when they are flooded with emotion? A new study says that, indeed, the eyes of our canine companions do well up with tears. In fact, it happens regularly when they're reunited with you.
Dogs and humans clearly have a special bond. But do dogs, like humans, produce more tears at times when they are flooded with emotion? A new study reported in Current Biology on August 22 -- which may be the first to look at this question -- says that, indeed, the eyes of our canine companions do well up with tears. In fact, it happens regularly when they're reunited with you.
"We found that dogs shed tears associated with positive emotions," says Takefumi Kikusui of Azabu University in Japan. "We also made the discovery of oxytocin as a possible mechanism underlying it."
Kikusui and colleagues made the discovery after one of his two standard poodles had puppies 6 years ago. He noticed that, when his dog was nursing the puppies, something changed in the dog's face; there were tears. Those tears don't fall as they often do in humans but they do get teary eyes.
"That gave me the idea that oxytocin might increase tears," Kikusui says.
Oxytocin, he explained, is known as the maternal or "love hormone." The researchers also knew from earlier observations that oxytocin is released in both dogs and their owners during interactions. So, they decided to run a reunification experiment and see if it brought dogs to tears.
First, they used a standard test to measure dogs' tear volume before and after reuniting with their owners. They found that tear volume indeed went up when they got back together with the familiar human and not with a person they didn't know.
When they added oxytocin to the dogs' eyes, their tear volume also went up. That finding supports the idea that the release of oxytocin plays a role in tear production when dogs and their people get back together.
They also asked people to rate pictures of dogs faces with and without artificial tears in them, and it turned out that people gave more positive responses when they saw dogs with teary eyes. These findings suggest that dogs' tear production helps to forge stronger connections between people and their dogs.
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Source:
https://www.sciencedaily.com/releases/2022/08/220822130249.htm
