A recent study has been looking at just how much dogs love their owners.
Dogs are often described as fiercely loyal and loving pets but to what extent that is true has been put to the test by two universities in Japan. Azabu University and Jichi Medical University have discovered just how joyful dogs can be.
Tears of joy
According to the research, dogs can cry tears of joy when they are reunited with their owners. The research team first measured how many tears were produced by their 18 test dogs when they were just at home as normal with their owners. They then measured the number of tears when the dogs were reunited with their owners following a 5 hour absence.
The measurement was taken by placing a special strip of absorbent paper within the dogs lower eyelids, and measuring how much moisture from tears soaked in to the paper. When the dogs were at home accompanied by their owners there were no tears shed. However, when there was an absence between owner and dog, the result showed that dogs shed tears.
Tears linked to dog emotions
The research was carried out following one of the research team noticing his own dog had tears in her eyes following the birth of a litter of puppies. This made him think that dog tears are related to their emotions, and specifically the hormone oxytocin.
Oxytocin is produced when the dogs have a sense of love or affection. The research noted that a side effect is for owners to want to care for their dogs more when they saw tears in their dogs eyes. Whether dogs create similar tears of joy when reunited with other dogs is yet to be determined.