Doggie Dentistry

Most people have, by now, seen the commercial for the bone that is made to clean your dog’s teeth.  The commercial suggests that if dogs want beautiful teeth, we ought to buy them dentures.  The pictures are really funny, but the topic itself is serious.  Just as in humans, good oral health can be a key ingredient in good overall health.  Here’s what you need to know.

Basic Anatomy

Adult dogs have 42 teeth, composed of incisors in the front, canines (the long teeth that look like fangs), premolars, and molars.  There is a slight variability in the number of teeth based on breed, but most dogs have a total of 42.

There should be six incisors in the top jaw and six in the bottom.  These teeth are used to peel the meat off of bones and to aid the dog in grooming himself or herself, as well as other dogs.

The four canine teeth, one in each quadrant of the mouth, help the dog defend against attack, but also are used to simply hold objects in the mouth, such as tug toys or Frisbees.

Next in line come the sixteen pre-molars, four behind each canine tooth.  The pre-molars are what your dog would use if he or she lived in the wild to tear up large chunks of meat.  In more civilized society, however, your dog uses the pre-molars to chew on bones and other toys.  The premolars serve the important function of keeping your dog’s tongue inside his or her mouth.  If these teeth are missing, such as in many Chinese Cresteds, the tongue may hang out of the side of the mouth.

In the back of the mouth are the molars, two on each side of the top jaw and three on each side of the bottom jaw.  Molars are the strongest of the dog’s teeth, used to crush bones or to pulverize dog biscuits.

Your dog’s bite, or the way the upper and lower jaws meet when the mouth is closed, can vary based on breed and on the unique shape of a specific dog’s mouth within a certain breed.  Usually, the bite pattern of a specific breed is part of the breed standard and a dog with a different type of bite may not be suitable for conformance shows.

A dog is said to have a level bite when the upper and lower incisors meet tip-to-tip.  An overbite results from the upper incisors being significantly in front of the lower incisors, while an undershot bite is the reverse condition. Undershot bites are common in dogs with short noses such as Pugs and Bulldogs.  A scissors bite occurs when the upper incisors are just slightly in front of the lower incisors, causing the tops of the lower teeth to touch the back of the upper teeth.  The scissors bite is most common in dogs.

Tooth structure

The inside of the tooth is called the pulp or root canal, which carries the blood vessels and nerves.  Around the canal is the dentin layer, which gives the tooth its structural strength.  The portion of the tooth that lives below the gum line is called the root, while the visible portion is called the crown.  Only the crown has a layer of enamel over it to protect the tooth.  The gum tissue that covers the root is called the gingiva.  It is this tissue that becomes inflamed when tartar is not removed in a timely manner.

Can you really tell a dog’s age by his or her teeth?

While you won’t get the dog’s exact age by checking his or her mouth, you can pick up helpful clues as to the age of the dog.  However, if the dog has lived a pampered life, he or she may appear to be younger because the teeth will be in good shape.  Conversely, a dog who has had to scrounge for food and has never owned a toothbrush may look older than he or she actually is.  The following generalities may help you decide the approximate age of a newly adopted dog.

The first puppy teeth generally begin to break through the gums at four to five weeks, starting in the front of the mouth.  These deciduous or milk teeth number only 28, as the puppy has no need for molars at this young age.  At about three months after birth, the front teeth or incisors begin to be replaced by permanent teeth, followed by the premolars, molars, and finally the adult canines.  A dog will generally have all of his or her permanent teeth by the age of six months.

While the permanent teeth are coming in, your dog may have some discomfort, causing him or her to begin chewing up everything you own.  To discourage chewing of your valuables, try wetting a washrag and placing it the freezer, then giving it to your dog to use as a soother.

The dog’s teeth should be clean and white throughout the first two to three years, although  you may see some yellowing of the back teeth.  By age five, the yellowing will probably be seen on all of the dog’s teeth, a result of tartar buildup.  As the dog continues to age, the biting surface of the dog’s teeth will begin to show signs of wear and tear, grinding down the pointed surfaces.  Beyond age ten, you may start to see tooth loss.

Dental disease

If you’ve ever had a toothache, you know how painful it is.  Your dog can experience the same types of dental problems you can, but he or she can’t tell you about it.  Therefore, you must be alert to the signs of dental disease to prevent your dog from suffering unnecessarily before getting treatment.

Symptoms of dental disease include bad breath, brown discoloration, cracked teeth, trouble chewing, bleeding gums, and pain or whimpering when the muzzle is touched.  One of the most common dental problems dogs face is the same as that faced by humans:  tooth decay.  Because many people don’t brush their dog’s teeth regularly, plaque begins to build up on the teeth and soon hardens into tartar, causing yellowing of the teeth.  Because your dog’s lifespan is so much shorter than yours, it is unlikely that tooth decay will develop into outright cavities.  However, when your dog eats, soft pieces of food may become stuck between the teeth or in the small pockets along the gumline that surround each tooth.  If these food particles aren’t removed, they can cause an infection, which leads to bad breath, softened gums and gum recession.  When the gumline recedes, the portion of the tooth that has no protective enamel is then exposed, which can lead to pain when the tooth encounters temperature extremes.

More important, however, is the fact that what starts out as a small dental infection can spread to the rest of the body, potentially even leading to your dog’s death if left untreated.

Retained baby teeth

In most cases, as an adult tooth comes in, the root of the baby tooth is reabsorbed by the dog’s body.  If the root is not reabsorbed, the adult tooth will not be able to push out the crown of the baby tooth and break through the gum.  Retention of baby teeth can cause the dog’s bite to be off, a condition known as malocclusion.  Because the dog’s mouth does not close properly, food is more likely to become stuck in the teeth, and tooth decay will occur faster in a dog with a maloccluded bite.

Broken teeth

Working dogs are the dogs most likely to break a tooth because they use their teeth to carry out their jobs, rather than just to chew their food like house dogs do.  A cracked or broken tooth may or may not cause your dog any pain.  If your dog continues to eat well and shows no signs of infection, it is not necessary to do anything about the broken or cracked tooth.

However, if your dog stops eating or will only eat soft food, becomes unable to perform his working duties, or shows any signs of infection, you may want to have a veterinary dentist crown the tooth to protect it from further damage.

Home Dental care

In order to keep your dog’s teeth healthy, you should try to remove tartar at home before it builds up to the level where it must be scaled off using dental instruments.  Pour some three percent hydrogen peroxide on a wash cloth and rub your dog’s teeth on a regular basis.

If desired, you can purchase commercial toothpaste and toothbrushes made specifically for dogs.  Baking soda also makes a good dog toothpaste.  Your dog’s teeth should be brushed at least once or twice a week.  See our doggies den article on caring for your dog’s teeth for more information.

To help prevent the build-up of tartar, give your dogs raw bones which can help to scrape the teeth.  Cooked bones can be quite hard and may break your dog’s teeth, and they may cause intestinal problems because they can splinter.  Raw bones are soft enough to resist splintering, yet hard enough to scrape the plaque and tartar off the teeth.  They also provide an important source of calcium.

Proper home dental care, combined with routine inspections of your dog’s teeth by a veterinarian, will allow your dog’s teeth to last a lifetime.

Doctors Foster and Smith’s Pet Education Center has a number of articles on canine dental care,  while PetPlace.com offers this guide to brushing your dog’s teeth.