Chewing is part of teething behavior for your pup, and it's also a young dog's way of exploring the world. At around four weeks of age, a puppy starts getting its milk teeth: twenty-eight needle-sharp little baby teeth, with no molars. These remain until the puppy begins teething at four months of age, a process that can continue in small dogs until around seven months of age. Next come the adult teeth, forty-two of them, including molars. Stock up on those chew toys! When those permanent teeth arrive, your little dog will probably want to chew vigorously once more, just to break them in!
Dogs chew for many reasons besides teething. They explore their world with all their senses, include their teeth and taste buds. Chewing also relieves stress and releases pent up energy.
Sometimes adult dogs chew because they are bored or anxious. To cut down on the damage this can inflict on your home and possessions, you should confine the chewer when you cannot keep an eye on him. While he is under house arrest, provide the usual fun chew toys and safe bones. Always offer praise when your dog chews acceptable objects. You may also apply a repellent product like Bitter Apple to furniture and baseboards so they won't taste so good to your little canine home-wrecker.
You can also use the repellent spray as a teaching tool. When the pup starts chewing on your shoe or a magazine, take the forbidden object away and spray him while giving a no-nonsense “No! Leave it!” Then grab a chew toy and dangle it before the dog in an inviting way. When the dog seeks the toy, give it to him and praise him lovingly. In seizing this teaching opportunity, your goal is to redirect the dog's attention to the appropriate toy, conveying the message that chewing is okay — just not on the forbidden object.