A reader recently asked me about the evidence supporting recommended therapy for dental disease in dogs. This is has become a common question given the increasing awareness among pet owners that dental disease is a real and important health problem, and the availability of high quality prophylaxis and treatment.
The American College of Veterinary Dentistry, the organization of board-certified veterinary dental specialists, has a great site with information for pet owners about dental disease. I also find a lot of clear and pretty evidence-based information on the site of Dr. Frasier Hale.
Dental disease is unquestionably common, with some research suggesting it is the most common disease in pet cats and dogs, vying with obesity for the top spot. It primarily takes the form of periodontal disease, and unfortunately it is very difficult to detect or evaluate the severity of this problem in an awake dog. Dogs and cats show few overt symptoms of dental disease. Probing of the tooth sockets and x-rays are necessary, just as they are for humans, to accurately characterize the type and severity of dental disease and determine the appropriate treatment.
Unfortunately, our pets almost never get twice daily brushing and flossing or semi-annual dental cleanings, and they often have very abnormal occlusion (the arrangement and interaction of the teeth in the mouth) as a result of breeding. Toy breed dogs and those with foreshortened faces are at especially high risk of severe dental disease due, in large part, to the same anatomy that makes them appear cute to humans. So proper diagnosis and treatment of dental disease requires general anesthesia, and it is very often necessary to remove infected teeth because the disease is advanced or because the level of care needed to preserve them cannot be accomplished.
Naturally, owners are often anxious or reluctant to pursue care that involves general anesthesia and likely extraction of teeth, due to worries about the safety and comfort of the pet and also due to the high cost of appropriate care. The fact that our pets rarely show recognizable symptoms, even with a level of disease that we know would cause tremendous discomfort in people, also makes it more difficult to convince people that dental care is necessary and beneficial for their pets. While the most obvious reason to pursue this care is that the disease is almost certainly painful, it is sometimes helpful to consider the secondary health risks associated with untreated periodontal disease. I recently took a quick look at the evidence concerning these.
There is pretty strong evidence in humans that untreated periodontal disease is associated with other health problems, notably cardiovascular disease, diabetes, respiratory disease (including infections) and pre-term low-birthweight deliveries. Treatment of periodontal disease leads to clinical improvements in several diseases as well. It is plausible that a similar relationship between dental disease and general health would hold true for cats and dogs, but there is little direct evidence.
At least two studies have identified pathological lesions in specific organs, including the liver, kidneys, and heart (1,2). This demonstrates that periodontal disease is associated with detectable abnormalities in the tissues of these organs. It seems likely that this could also affect the function of these organs and the well-being of the individuals with such lesions, but this was not evaluated by these studies.
At least one study has taken the next step and evaluated the association between periodontitis and actual disease in another organ system (3). A strong, linear association was identified between dental disease and chronic kidney disease, and while this does not prove dental disease causes kidney disease, it suggests that untreated periodontitis may be an important risk factor for kidney disease in dogs.
A similar study also suggested that periodontal disease may be associated with cardiac disease as well as pathologic lesions in the heart (4). However, there were significant methodological problems with this study, and other investigations have not found a link between dental disease and heart disease in dogs, so there is still controversy about this potential association (5,6).
Finally, one study has looked at common bloodwork variables and measures on inflammation in association with periodontal disease and its treatment (7). A few significant associations were identified, but there was no clear pattern suggesting a causal relationship between periodontitis and any particular disease.
Dental disease, especially periodontal disease, is very common in dogs and cats. Though affected pets rarely show obvious or severe symptoms, periodontal disease is undoubtedly a source of significant discomfort. The only accurate way to diagnose, characterize, and treat periodontal disease is with a thorough oral examination, dental x-rays, and appropriate cleaning and often extraction or endodontic treatment of infected teeth. This can only be accomplished under general anesthesia.
There is good reason to believe proper prevention and treatment of periodontal disease makes dogs and cats more comfortable. In humans, it is also clear that such prevention and treatment improves health and reduces the risk and severity of other specific diseases. It is likely this is also true in dogs and cats, but the current research evidence regarding this claim is extremely limited.
- DeBowes LJ, Mosier D, Logan E, Harvey CE, Lowry S, Richardson DC. Association of periodontal disease and histologic lesions in multiple organs from 45 dogs. J Vet Dent 1996; 13:57-60.
- Pavlica Z, Petelin M, Juntes P, Eržen D, et al. Periodontal disease burden and pathological changes in organs of dogs. J Vet Dent 2008; 25: 97-105.
- Glickman LT, Glickman NW, Moore GE, Lund EM, Lantz GC, Pressler BM. Association between chronic azotemic kidney disease and the severity of periodontal disease in dogs. Prev Vet Med 2011; 99: 193-200.
- Glickman LT, Glickman NW, Moore GE, Goldstein GS, Lewis HB. Evaluation of the risk of endocarditis and other cardiovascular events on the basis of the severity of periodontal disease in dogs. J Am Vet Med Assoc 2009; 234: 486-494.
- Pavlica Z, Petelin M, Juntes P, Erzen D, Crossley DA, Skaleric U. Periodontal disease burden and pathological changes in organs of dogs. J Vet Dent. 2008 Jun;25(2):97-105.
- Peddle GD, Drobatz KJ, Harvey CE, Adams A, Sleeper MM. Association of periodontal disease, oral procedures, and other clinical findings with bacterial endocarditis in dogs. J Am Vet Med Assoc. 2009 Jan 1;234(1):100-7.
- Rawlinson JE, Goldstein RE, Reiter AM, Attwater DZ, Harvey CE. Association of periodontal disease with systemic health indices in dogs and the systemic response to treatment of periodontal disease. J Am Vet Med Assoc 2011; 238: 601-609.