Dogs ‘cry’ tears of joy when they reunite with their owners, Japan scientists find
- The researchers found a connection between a dog’s emotions and the volume of tears it produces, with more being produced upon meeting their owners
- They hypothesised that oxytocin – the hormone that helps with bonding and feelings of love – is related to a dog’s tear production
The researchers said that they’ve found a connection between a dog’s emotions and the volume of tears it produces, in their study published in the peer-reviewed journal Current Biology.
Dogs have tear ducts that can well up with tears just like humans do, but this is the first time that an animal’s tear production has been tied to its happiness.
The team said they conducted the Schirmer test – which involves placing a paper filter on a dog’s lower eyelid to collect moisture – on 18 dogs who were reunited with their owners after being separated for five to seven hours.
They said the dogs secreted significantly larger tear volumes in the first five minutes of meeting their owners again, compared to when they were alone.
The researchers also ran another experiment in which 20 dogs met a human they weren’t familiar with. This time, the dogs didn’t produce more tears than normal, they said.
The team also hypothesised that oxytocin – the hormone that helps with bonding and feelings of love – is related to a dog’s tear production.
