Dog Smiles for the Camera

When the person taking this picture said, 'Smile for the camera,' they probably were only expecting to see one set of gnashers. But thanks to his unexpected human-like expression of happiness, this gleeful dog has become an internet sensation.

The chirpy canine, pictured grinning ear to ear with his smiling Martina Navratilova lookalike owner, is now something of a star after his picture began being shared on social networking sites like Facebook and Twitter.

However, this hound's fame is nothing yet compared to that of Riley, the bichon frise/poodle mix pictured smiling while celebrating its first birthday.

The young dog was photographed in a party hat, unable to contain his excitement, as he prepares to devour a cake by its owner Maureen Ravelo, from San Jose, California. The image has since spread like wildfire.

‘Riley always makes faces like this, and that’s the best part about him. He gives you a new facial expression every time that you forget he’s a dog,’ Ms Ravelo told Metro.

‘The most unique part about him is he thinks he’s human like us,’ she added.