DVM: What is the best way to approach the treatment of severe periodontal disease? Do certain breeds have special needs that
should be considered?
Harvey: There are two aspects to professional treatment. One is cleaning, including scaling and polishing to remove the plaque and
calculus that are causing periodontal disease. Then for severe disease there is surgery or some other procedure to stabilize
the tooth sufficient to allow it to be maintained.
It's not inherently easy to figure out what to do to retain a tooth. Radiographs are essential. If you're going to treat a
tooth that is severely diseased, then you need to know how much of the root is still in place, how much of the bone around
the tooth is healthy and whether endodontic disease is present. You want to be sure that the work you're going to do will
produce a more healthy bone and soft-tissue combination around that tooth. We're not looking for some quick result here. We're
looking to retain that tooth over the remaining life span of the patient.
I like to think in terms of triaging teeth. There are 42 teeth in the mouth of the dog, and what I hope is that veterinarians
pay attention to the most severely affected teeth first, particularly in older dogs or dogs that have systemic problems where
we might have concerns about anesthesia. So if we only have a half an hour under anesthesia, we know at the end we've dealt
with what's going to be most beneficial to the dog. And we haven't lost the opportunity to do something good because we use
an identical approach with every patient – always starting at the top right of the mouth and going all the way around.
We have a particular problem when treating toy breeds with periodontal disease. The epidemiological evidence is very clear
that small dogs are more likely to be affected than larger dogs. But, as a result of the selected breeding that produced the
smaller dogs, the amount of bone in the bodies of the toy breeds genetically down-sized more than the teeth. That means there's
less bone around the teeth in toy breed dogs, so the same amount of inflammation will have a proportionately more serious
effect in toy breeds than in larger dogs. And the impact may be more severe because the jaw may not have enough strength to
resist fracture. The classical problem is a 15-year-old Yorkshire terrier or other toy breed with plaque and calculus, and
the dog is anesthetized for a combination extraction/scaling procedure. But as the lower jaw is pulled down to insert the
endotracheal tube, the traction is enough to cause a pathological fracture, usually around the first molar tooth. So it's
important that veterinarians are careful when they're handling the jaws of older toy breed dogs with severe periodontal disease.
It's good to pay special attention to the small and toy breed dogs early on and get owners to understand the value of disease
DVM: Are there any strong indicators or studies showing that periodontal disease affects other body systems?
Harvey: There are two studies in dogs that have looked at microscopic changes in the heart, liver and kidneys. They found that with
more severe periodontal disease there is an increase in inflammatory or degenerative changes in those organs compared to less
severely affected dogs. There is also evidence of an increase in C-reactive protein, which is produced by the liver in response
to stress or inflammation anywhere in the body.
In dogs that were anesthetized for periodontal treatment and then were re-examined the C-RP level was reduced, suggesting
that the periodontal treatment eliminated a cause of C-RP production. That's as close as we've come to proving a cause-and-effect
relationship. It would take a large-scale and expensive study to actually prove this cause-and-effect relationship, but the
association does infer that periodontal disease is a risk factor for microscopic scarring in the distant organs.
It's very easy to get caught up in hyperbole in statements like "Periodontal disease causes heart disease," or "Periodontal
disease causes renal disease," and have that repeated to the point where it becomes hugely overstated. Many dogs have some
degree of periodontal disease and some measurable abnormality associated with periodontal disease. A much smaller number of
dogs have severe periodontal disease and may have had it long enough that daily bacteremia (shedding of bacteria into the
bloodstream) as a result of chewing may have triggered some distant change in the body's tissues.
It's difficult to maintain perspective because people want a simple statement, and it just doesn't work that way yet. If indeed
there is a cause-and-effect relationship, then it's worth our while to do something that's pretty easy to do anyway (preventive
care) and has a big benefit. Preventing the accumulation of dental plaque and calculus is a habit that we accept for the health
of our own teeth, and we can do this for our dogs whether its daily brushing, rubbing the teeth with a cloth, by giving dental
treats, feeding a dental diet or using other products with proven dental efficacy – just look for the VOHC Accepted Seal.
Linda Marie Wetzel is a freelance writer in Cleveland, Ohio.