There is a saying English that says a dog is a man's (and woman's) best friend. Dogs and humans have shared close and loving relationships thousands of years. Scientists believe the bond between humans and dogs is deeper than we thought. The scientists discovered that dogs cry tears joy when they see their owners after a period absence. The scientists conducted a small-scale study 22 dogs. They tested the behaviour the dogs. particular, they looked how the dogs reacted when they were reunited their owners and with other people they had daily contact . The scientists said that when the dogs saw their owners, they cried.
The researchers, Azabu University and Jichi Medical University, put strips paper under the dogs' eyes. They then checked to see if, and when, the dogs cried. The scientists found that when the humans and dogs were reunited five to seven hours separation, the dogs shed tears. Researcher Takefumi Kikusui said: "We had never heard the discovery that animals shed tears joyful situations, such as reuniting with their owners." He added: "Their tears might play a role the deepening mutual relationships." He believes the tears may make humans love their dogs more. He said: "It's possible that dogs who show teary eyes human interaction would be cared more."