Researchers analysed activity in regions of brain when dogs were shown images of different facial expressions

While dogs are known to turn the puppy eyes on their owners, it seems our pets are keeping a close eye on us too: research has revealed dog brains can distinguish different types of unhappy human faces.

Dr Laura Cuaya, a co-author of the study from the University of Vienna, said previous behavioural studies had shown dogs could tell apart some human facial expressions, but such studies tended to only test two at a time, one positive and one negative. As a result, it was not clear if dogs could distinguish different types of happy or unhappy faces.