For dog owners who always tell you that their pet is almost human, now there is hard evidence that they may be right.
In tests humans were able to accurately read a dog’s emotions just by looking at his face.
Fifty volunteers were shown pictures of a five-year-old Belgian Shepherd police dog called Mal as he went through a range of emotions, triggered by praise, reprimands, a jack-in-the-box and even nail trimmers which he particularly liked.
88 percent of the volunteers were able to spot happiness - shown by Mal looking straight at the camera with his ears up and tongue out, the Daily Express reported.
Almost as easy to spot was anger - provoked by a man pretending to be a criminal - with 70 percent correctly interpret Mal’s bared teeth.
About 45 percent knew that Mal pricking his ears up and showing the whites of his eyes revealed fear while 37 percent knew that a mournful expression with downcast eyes showed sadness.
Less easy to read were surprise - shown by a frown - and disgust - revealed by flattened ears.
In the tests people with minimal experience of dogs were better at reading canine disgust and anger than dog owners.
This suggests that understanding dogs may come naturally rather than being learned.
“There is no doubt that humans have the ability to recognise emotional states in other humans and accurately read other humans’ facial expressions,” Researcher leader Dr Tina Bloom of Walden University in Minnesota said.
“We have shown that humans are also able to accurately - if not perfectly - identify at least one dog’s facial expressions,” she said.
Surrey-based animal psychologist Dr Roger Mugford said the faces of dogs are much easier to read than those of other animals such as cats or horses.
He said tests have shown that even people from cultures which do not have pet dogs can correctly read their faces.
The findings are published in the journal Behavioural Processes.