Scientists have discovered that dogs experience a range of complex emotions, including jealousy, pride and affection.
Researchers at the University of Vienna in Austria got 33 trained dogs to extend a paw to a human for a reward. But when asked to do so again, some dogs were found to be unenthusiastic when some were rewarded but they were not.
Dogs that were not rewarded also showed signs of stress such as licking or scratching themselves.
Paul Morris, psychologist at the University of Portsmouth, tells CNN that the research is surprising.
“We are learning that dogs, horses, and perhaps many other species are far more emotionally complex than we ever realised. They can suffer simple forms of many emotions we once thought only primates could experience.”