Scientists have found out that dogs can cry with happiness

Everyone knows that dogs can cry. But previously it was believed that this happens solely because of negative emotions. Scientists from Azabu University found out that dogs can also cry if they are happy. These animals can cry if, after a long separation, they saw the owner or just a person who was kind to them.

The journal Current Biology published the results of a study conducted by Japanese zoologists. They measured the amount of tears in the dogs' eyes using the Schirmer test. To do this, special strips are placed under the eyelids. This method was developed in order to diagnose lacrimal fluid deficiency. But as it turned out, the test can also help in other situations.

Japanese researchers took as a basis the amount of fluid in the eyes of dogs during normal communication with the owner. The reference number of tears was compared with those that appear in the eyes of the animal 5-7 hours after separation. It turns out that during the first few minutes after reuniting with a person, dogs significantly increase the production of tears.

The idea of such an unusual experiment came from biologist Takefumi Kikusui. He noticed that his poodle cries when feeding puppies. This prompted the scientist to think that the hormone oxytocin is able to increase the number of tears.

It turned out that the number of tears released by the eyes of dogs is greater when meeting with the owner than when contacting other family members. Japanese biologists have also determined that the tears of pets also affect people. When dog owners were shown photos of their pets, it was the pictures with tears that caused a greater response. There is an assumption that this is not for nothing and tears help animals establish a stronger connection with humans.

Dogs are pets that need a special approach. Here are 10 tips to help you find a common language with pets.