Teeth line the upper and lower jaws of dogs and are used for tearing and shredding food. Puppies have 28 teeth, while adults have 42. The exact number can vary slightly. The teeth are living tissue
and are covered with enamel, the hardest substance in the dog's body. Dentine is the next layer, and the core is called the pulp. The pulp contains blood vessels and nerves which nourish the teeth. The root of the tooth is buried beneath the gum. Some teeth, such as incisors, have one root, while the others, such as the upper fourth premolars, have as many as three roots.
Teething in the puppy refers to the process of growing baby teeth (deciduous teeth) and ends with the adult or permanent teeth. The first baby teeth, sometimes referred to as 'milk teeth,' erupt from the gumline around four weeks of age. These teeth are small and very sharp. They may scratch the nipples, resulting in discomfort to the nursing mother. By about six weeks of age, the baby teeth are sufficiently painful to the mother's nipples to cause her to begin to wean the puppies from the nursing process.
The first deciduous teeth to come in are the canine teeth and incisors, followed by the premolars and molars. Puppies generally start to lose the deciduous teeth at age 2-3 months of age. As with the deciduous teeth, the incisors are the first permanent teeth to erupt. They are followed by the canines, molars, and premolars.
Most puppies are undergoing some form of continued teething, either erupting or replacing the baby teeth, until they are about nine months of age. The exact end to teething varies considerably with each individual puppy. Teething puppies love to chew. This may be an attempt to relieve the irritation associated with raw and occasionally bleeding gums. It is best to provide the puppy with sufficient chews in the form of nutritional treats, toys, etc. This will help direct the potentially destructive chewing habit away from objects such as furniture.