Ernie Janes / Yellow Labrador puppy with teddy bear.

Alex Mustard / Male Grey seal (Halichoerus grypus) playing with an orange chew toy offered by a diver, Lundy Island, Devon, England, UK. July 2010

Jane Burton / Sable Border Collie pup, 11 weeks old, chewing on toy in his bed in puppy crate, with toys and a chew

Jane Burton / Mixed breed puppy lying down and chewing on chew-toy.

Mark Raycroft / Golden Retriever (Canis familiaris) adult with training bumper

Mark Raycroft / Great Dane (Canis familiaris) puppy with largest rawhide chew toy

Petra Wegner / Two Coton de Tulear puppies, 8 weeks, fighting over a rawhide chew