In Photos: National Puppy Day

A yawning jack russell terrier. In 2008, the University of London found that human yawning is ‘contagious’ to dogs. It was the first study to show that the human yawn impulse could be transferred to another species by a visual cue alone.

Photograph: Eureka / Alamy/Alamy

The phenomena of ‘puppy dog eyes’ is a scientific fact. In 2017 the Dog Cognition Centre at the University of Portsmouth published research that showed that dogs vary their facial expressions specifically to communicate with humans.

Photograph: Chris Radburn/PA