**Abstract**

Periodontal disease is one of the most common health problem affecting dogs. The disease is more prevalent in small breeds and brachycephalic breeds compared to large breeds, and incidence increases with advancing age. In first stage it affects only the gingival tissue and causes gingivitis. It later develops into periodontitis which involves changes in other periodontium tissues. Main etiological agents of periodontal disease are pathogenic bacteria of dental biofilm, and products of their metabolism. In human, *Porphyromonas gingivalis*, *Treponema denticola* and *Tannerella forsythia* play a key role in the etiology of periodontal disease. Also, there are many other candidates as human periodontal pathogens, including *Aggregatibacter actinomycetemcomitans*, *Prevotella intermedia*, *Prevotella nigrescens*, *Fusobacterium nucleatum*, *Parvimonas micra*, *Eikenella corrodens*, *Capnocytophaga gingivalis*, *Eubacterium nodatum* and *Campylobacter rectus*. Since periodontal diseases in dogs are similar to human diseases in terms of disease progression and clinical manifestation, we can assume their common etiology. This chapter is focused on review about canine dental biofilm and about members of biofilm as potential causative agent of canine periodontal disease.

**Keywords:** dental plaque, biofilm, dog, periodontal disease, gingivitis, periodontitis
