Puppies teeth between the ages of three and six months, and they need to chew on something to help the teeth come through. A puppy isn't a picky chewer - he doesn't understand whether it's your best shoe or the leg of your antique sofa that he gnaws on.
Help to avoid destruction by giving your puppy a choice of good, indestructible objects to chew on - a really hard rubber ball (one that's too big for the pup to swallow and choke on) or a though rubber bone. Help your pup avoid the wrong things by keeping them out of reach. Especially make sure that cleansers, paint thinners, household chemicals and other harmful substances are safely locked up.