Revealed: What your pet's 'puppy dog eyes' really mean

When your dog puts on “puppy dog eyes”, owners often melt inside – and that seems to be exactly the effect dogs are aiming for.

The animals rarely use the expression when they’re on their own, a new study has shown – suggesting that it’s for their owners’ benefit.

Previously, scientists had assumed that animal facial expressions were involuntary.

But researchers at the Dog Cognition Centre at Portsmouth University found that dogs mostly use the expression in response to human attention.

The “puppy dog eyes” expression, where the dogs raise their brows to make their eyes appear wider, was the most commonly used expression.

“We can now be confident that the production of facial expressions made by dogs are dependent on the attention state of their audience and are not just a result of dogs being excited,” researcher Dr Juliane Kaminski said.

“In our study they produced far more expressions when someone was watching, but seeing food treats did not have the same effect.

“The findings appear to support evidence dogs are sensitive to humans’ attention and that expressions are potentially active attempts to communicate, not simple emotional displays.”