Ecology of genus Porphyromonas in canine periodontal disease

Asaccharolytic pigmented Porphyromonas species, including P. endodontalis, P. gingivalis, P, circumdentaria and unclassified species, were isolated fr om the plaque of adult dogs, but not from any oral sites of puppies and ado lescent dogs. With age-dependency, the proportion of Porphyromonas species in the flora of plaque increased. Isolation of the genus Porphyromonas was clearly associated with the progress of periodontol disease. We suggested t hat Porphyromonas is the exogenous organism and obligate pathogen for canin e periodontal diseases.