This news item is about: Some chewing is part of being a dog, and some is a sign of a bigger problem. How you should handle it depends on the cause. “Puppies chew. It’s how they explore, just like human babies,” says Brian Collins, DVM, a veterinarian at Cornell University Companion Animal Hospital. Older dogs do it, too. “They may do it just to pass the time,” he says. Dogs also gnaw to keep their teeth clean and their jaws strong.