Periodontal Disease in the Dog and Cat
Periodontal Disease is defined as an inflammation and/or infection of the gums and bone around the teeth. Periodontal disease is the most common disease found in the dog and will affect more than 8 out of 10 dogs three years of age and older. The prevalence of periodontal disease in the dog increases with age but also decreases with increasing body weight; therefore, toy and miniature breeds are more severely affected.
Periodontal disease usually starts as inflammation of the gums called gingivitis. The gums themselves may become reddened and swollen. Plaque, which consists of material deposits on the surfaces of the teeth, and tarter, consisting of material deposits below the line of a tooth, are formed from material in the mouth. This material is comprised of calcium phosphate and carbonate and collects additional organic matter and bacteria, thereby resulting in the formation of dental calculus. Gram negative anaerobic bacteria are the principal types of bacteria involved in the pathogenesis of periodontitis. These bacteria produce endotoxins which in turn elicit an inflammatory response in the infected dog. Not only will these bacteria cause inflammation and destruction of the tooth-supporting structures, or periodontum, but they may also cause systemic disease.
Clinical signs of periodontal disease start as inflammation of the gum tissue which spreads to the bone around the teeth. Untreated teeth will become loose, causing pain especially when the pet is eating. The pet will have noticeably bad breath, or halitosis, and bleeding of the gums often occurs. As the disease progresses teeth will eventually be lost.
Systemic disease may develop because the gums are very vascular (have a good blood supply). Blood will carry these anaerobic bacteria via the blood stream where they are then filtered out by the kidneys and liver. Once removed by the liver or kidney they will then colonize in that particular organ developing microabscesses. The bacteria traveling through the blood may also attach to the heart valves resulting in vegetative endocarditis (infected heart valves). Additional diseases that may result from periodontitis includes chronic bronchitis and pulmonary fibrosis.
In a 2008 study by Glickman and associates the medical records of over 59,000 dogs with periodontal disease were reviewed confirming that there is a direct correlation with periodontal disease and the subsequent occurrence of endocarditis and cardiomyopathy in dogs. They found that dogs with stage 3 periodontal disease had a 6-fold higher risk for infective endocarditis.
The single best thing to prevent the progression of periodontal disease is to brush the teeth. Brushing will reduce plaque buildup. When necessary, professional cleaning will help remove material under the gum line. Antibiotics should be used with periodontitis or when it becomes necessary to clean the teeth below the gum line to prevent systemic spread of the bacteria.
The most common type of bacteria found in dental calculus is Porphyromonas denticanis. Pfizer Animal Health has recently marketed a new bacterin against the Porphyromonas bacteria, which is the most commonly implemented bacterium in periodontal disease. The use of this bacterin (similar to a vaccine but comprised of bacterial components instead of viral ones) helps prevent bone and tooth loss due to the secondary bacterial infection found in dental calculus. Dogs receive two doses of the vaccine at three-week intervals, and future vaccine usage is dependent upon your veterinarian’s analysis of the frequency necessary to prevent bone and tooth loss. In a clinical trial this bacterin resulted in significant improvement in bone reactivity scores as compared to non-vaccinated dogs. This vaccine can play an important role in maintaining dental health but must be combined with professional dental cleaning and home preventive care (brushing) for optimal control of periodontitis.
Glickman, Lawrence and Rita Glickman, et al. “Evaluation of the risk of Endocarditis and other Cardiovascular events on the basis of the severity of Periodontal Disease in Dogs.” JAVMA. Vol. 234. Feb. 15, 2009. Pp. 487-494.