Diagnosis of periodontal disease in dogs.

We would like to comment on the article ‘‘Periodontal disease in research beagle dogs – an epidemiological study’’, which was published in the December issue of the Journal of Small Animal Practice (Kortegaard and others 2008). The authors attempted to document the prevalence and severity of periodontal disease in anaesthetised beagle dogs based on a full-mouth, site-specific examination. To achieve these goals, the authors used clinical attachment loss, pocket depth and bleeding on probing as the main diagnostic indices of periodontal disease. Conspicuous in its absence is the use of dental radiographs. The definitive diagnosis of periodontal disease is based on the combination of clinical findings and dental radiography (Armitage 2003, Wolf and others 2005). Unfortunately, the issue of dental radiography as an essential and integral part of the diagnosis of periodontal disease was not addressed in this article. Dental radiography is the standard technique used in clinical practice for documenting bony changes associated with periodontal disease, and the combination of periodontal probing and dental radiographs constitutes the standard of care in humans (Armitage 2003). In this day and age, it should also be considered the standard of care in dogs (Verstraete and others 1998). Radiographs provide unique information about the status of the periodontium and a permanent record of the condition of the bone throughout the course of the disease. In addition, dental radiographs aid in identifying the extent of destruction of alveolar bone, local contributing factors and features of the periodontium that influence the prognosis of periodontal disease (Carranza and Takei 2002, White and Pharoah 2004). Radiographs provide additional information on the extent of supporting bone loss in 92 per cent of dogs with periodontal disease. In 26 2 per cent of dogs with periodontal disease, the radiological findings showed the extent of periodontal disease and bone loss to be greater than what was clinically diagnosed (Verstraete and others 1998). The clinical value of interpreting alveolar margin height from dental radiographs in combination with periodontal probing measurements for assessing periodontal attachment in dogs is high (Tsugawa and others 2003). This is in agreement with the findings in humans where there is approximately 80 per cent concordance or agreement between probing and radiography in identifying the severity of periodontal disease and around 20 per cent that are more severe than initially estimated (Jeffcoat 1992, Hausmann and others 1994). Furthermore, full-mouth radiography also demonstrates other dental lesions related or unrelated to periodontal disease. Radiography of teeth or areas without clinically evident dental disease revealed incidental findings in 41 7 per cent of dogs and clinically important lesions in 27 8 per cent, further emphasising the importance of dental radiography in dental evaluations (Verstraete and others 1998). Any study attempting to document the prevalence and severity of dental disease in animals under general anaesthesia should be considered incomplete without dental radiographs.