Dogs cry when they find their owner, says study

Tears of happiness. Rapid flapping of the tail, jumps in the air and irrepressible licks: every dog ​​owner regularly experiences this joyful reunion with his animal, after a few hours of separation. But to this list of highly demonstrative behaviors there is also a more discreet sign. Dogs also produce tears when they find their master, according to a study published Monday August 22 in the journal Current Biology.

“We had never heard of pets shedding tears in happy situations, like reuniting with their owner,” one of the study’s authors, Takefumi Kikusui, of Azabu University in Japan, said in a statement, citing a possible “world premiere”.

The scientists measured the amount of tears produced using a widely used test, the Schirmer test (consisting of a strip placed under the eyelid). They took as a point of comparison a base level raised when the dog was in its usual environment, in the presence of its owner.

After five to seven hours of separation, the amount of tears increased “significantly” within five minutes of reuniting the dog with its master. The volume of tears was also higher when the dog was reunited with its master, rather than another person.

According to the researchers, this production of tears is linked to the presence of oxytocin, nicknamed “the hormone of love”. Dogs, domesticated like no other animal, have developed specific communication skills over time. Eye contact has been shown to play a role in forming the relationship between a dog and its handler.