Dogs Cry Tears Of Joy When Reunited With Their Owners
A wagging tail, a jump, or barking are all telltale signs your dog is happy to see you. Now, researchers from Japan have discovered a new indicator of happiness in dogs: tears of joy. Like humans, dogs have tear ducts that well up with tears to keep their eyes clean and healthy. But tears in dogs hadn't been linked with emotion before, until now. "We found that dogs shed tears associated with positive emotions," Takefumi Kikusui, coauthor of the research. The study also found that oxytocin - often called the love or maternal hormone - was responsible for the tears. Kikusui and his team measured the amount of tears among dogs using the so-called Schirmer Tear Test. This involved placing a paper strip inside the dogs' eyelids for a minute before and after they were reunited with their owners. Then, the amount of tears before and after reunions with their owners was compared. Only the reunion with the owner increased the amount of tears.