However, in this list of obvious behaviors there is a more discreet one. Dogs also produce tears when they are reunited with their ownersresearchers showed in a study published Monday by the journal Current Biology.
“We have never heard of animals shedding tears in happy situations, such as when reunited with their owners,” one of the study’s authors, Takefumi Kikusui, of Azabu University in Japan, said in a statement.
The researchers measured the amount of tears under the eyelids using a common test called the Schirmer test and then compared an elevated level, such as when the dog meets its owner or its usual space.
After a period of five to seven hours of separation, the number of tears increased “significantly” after five minutes of being reunited with their owner. The volume of crying was also greater when comparing the reunion with its owner to that with another person.
According to the researchers, Tear production is linked to the presence of “the love hormone” or oxytocin.
They also tried to understand the functional part of these tears. To do this, they asked the owners to order photos of their dog based on which of them they felt most eager to take care of it.
Photos in which artificial tears were applied to dogs were ranked “significantly” higher, according to the study.
Dogs showing wet eyes during interactions may make them look after them more
“It is possible that dogs that show their wet eyes during interactions make them take more care of them,” Takefumi Kikusui explained about this characteristic present in human babies.
Dogs, domesticated like no other animal, have developed specific communication skills and eye contact has been shown to shape the relationship between animal and owner.
The researchers now want to study whether dogs produce tears when they meet other dogs.