Philadelphia — Dr. Colin Harvey, BVSc. FRCVS, Dipl. ACVS, Dipl. AVDC, is an expert in oral, dental and periodontal diseases of dogs and
cats and the relationship of those diseases to systemic health. He is currently professor of surgery and dentistry at the
School of Veterinary Medicine of the University of Pennsylvania in Philadelphia, as well as the director of the Veterinary
Oral Health Council (VOHC). Dr. Harvey recently spoke with DVM Newsmagazine about treatment of severe periodontal disease and shared his insights about dealing with the special needs of afflicted animals.
Dr. Colin Harvey
DVM: Will you describe the characteristics of severe periodontal disease in dogs and cats?
Harvey: The major characteristic of severe periodontal disease is the reaction of the body to plaque and calculus buildup. The longer
extensive buildups are present, then the more likely it is that there will be not just gingivitis – inflammation of the tissue
– but a more harmful response where the body's own tissues are melting away as a result of the inflammation. That is the
problem with severe periodontal disease. If you eliminate the plaque and calculus, then you can stop the inflammation. Meanwhile,
there may not be a mechanically stable tooth in place.
But the local immune response is different between individuals so that one dog may have a lot of calculus buildup on it's
teeth and have very little signs of infection, while another dog may have a lesser amount of calculus present, but the teeth
may already be loose.
This points to the need for, and the value of, a routine visual examination which I hope would be done any time a pet comes
in for any reason. It takes only a moment to simply lift the lip to see what's going on with the upper teeth – those are more
likely to be severely affected in animals with periodontal disease. It gives you an excellent sense of what's going on in
the mouth. If what you see is disease and a lot of calculus then, clearly, there is need for some professional intervention.
If not, then there's no further need beyond opening the mouth. But the critical point is to get the process started no matter
the reason for the animal being on the exam table.
DVM: How can chronic medical conditions complicate the treatment of periodontal disease?
Harvey: There are clearly some conditions that will adversely affect the health of the mouth. For example, in chronic renal failure
the increased urea level in the blood affects urea levels in saliva. When the urea in the saliva breaks down to ammonia, this
causes the nasty smell in the mouth which you find in dogs that have severe renal disease. But this can also be severe enough
to cause chemical burning of the tissues in the mouth. Further, the chemically difficult environment suppresses the local
defense mechanisms and makes mouth tissues that are much less able to fight off infection. And in diabetic animals, the elevated
blood sugar means there's more substrate in the mouth for bacteria to feed on.
There's also a danger that periodontal disease may mask a primary medical problem. Particularly in middle-aged or older dogs
with halitosis, it's critical to look at the overall health of the dog before starting to treat the periodontal disease. If
people have a sense from their own dental treatment of what's going to happen to their pet, then that needs to be expanded
to include a discussion about anesthesia and how to manage it. The first requirement for veterinarians is to justify the preoperative
tests that are necessary. If I'm going to put an animal under anesthesia, particularly if it's middle-aged or older or if
it's showing any kinds of symptoms like polydipsia, polyphagia, not eating, losing weight or throwing up, then it's an easy
The health of the dog is the major determinant of what we can do, how long we have to do it, how involved the anesthesia will
be and what kind of support we need to provide during that anesthesia. And in some dogs that means we look to extraction as
a way of dealing with oral infections in the most dependable manner. We have to consider the whole patient rather than just
what would be best for likelihood of healthy retention of the teeth.