Ask Dr. Norm: It's a dog's teeth's world

Dear Dr. Stillman: Do I need to brush my dog's teeth? — Molly H.

Dear Molly,

Thanks for your question. February is National Pet Dental Health Month, so it's very appropriate. You specifically asked about your dog, but in this case everything I'll tell you will apply equally to a cat as well.

I do encourage folks to brush their pets' teeth, but there's more than one way to try to promote good dental health and prevent the onset of dental decay and periodontal disease. As I'm sure you know, the reason that we brush our pets' teeth (or our own) is to temporarily remove the layer of disease-causing bacteria that inhabit our mouths and build up on the surface of our teeth in a film called the pellicle. These bacteria, if left to their own devices, excrete chemicals that break down the surface of the tooth causing pitting and decay. If we brush frequently and thoroughly enough we can almost indefinitely delay the onset of dental disease.

Tartar is a mixture of bacteria and the minerals that they form into a porous framework designed to protect and shelter them. As tartar accumulates it spreads along the tooth, working its way in between the tooth and its bony socket and destroying the soft tissue attachment (called the periodontal ligament), which holds the tooth in place and prevents it from moving. When the tartar has disrupted enough of this attachment the tooth becomes loose, and not long after that it may even fall out. The process is painful and may lead to swollen and inflamed gums.

Additionally, the mouth is an unusual area of the body in that it contains both an active bacterial population and a very strong blood supply. It is vital for our pets' health that the bacteria not be allowed to enter the bloodstream, so normally the body presents several elaborate and highly effective barriers to their passage out of the oral cavity and into circulation. When the gums become inflamed these barriers begin to break down, allowing bacteria to enter the bloodstream. Purifying organs like the kidneys and liver filter the bacteria back out again but in the process may become damaged and infected themselves. In animals as well as in humans severe periodontal disease is one of the strongest risk factors for the development of liver and kidney infections.

Now, back to your question. Brushing a pet's teeth disrupts the above processes and makes the bacteria start daily from scratch. It's the most useful way to permanently delay the onset of periodontal disease and tooth decay. However, even the most ardent advocate of pet tooth brushing will readily admit that if you're not doing it on a daily basis it's not very useful. Doing it once or twice a week, or less, does not significantly slow the progression of disease. Not every pet (including my own cats and dog) will allow you to brush its teeth. For those pets there are other options.

Several manufacturers make prescription dental diets. I feed my own cats and dog the feline and canine versions respectively. These diets, designed to remove dental tartar and prevent it from reaccumulating, are not as effective as tooth brushing but are still very good. I strongly recommend these diets and find them very useful in the prevention of dental disease. They are cost-effective, tasty and nutritionally complete, and perform a very important and useful function.

Lastly, for pets that will not allow tooth brushing and for whom dental diets are not a good alternative, there is always the option of periodic dental cleanings. This procedure involves a brief period of anesthesia during which a pet's teeth are careful cleaned above and below the gumline and then polished back to a glassy sheen. Diseased or damaged teeth may be removed. This is my least favorite means of addressing dental disease, since it treats disease that is already present instead of preventing it from occurring.

In summary, I applaud your efforts to brush your pets' teeth on a daily basis. If that's not possible you should discuss alternative ways of preventing or treating dental disease in your four legged companions.

Dr. Norm Stillman is a veterinarian at the Court Street Animal Hospital, located at 136 Court St. in Plymouth, Mass. He can be reached by phone at 508-747-0774 or by email at courtstreetvet@verizon.net.