Periodontal Disease – Part I

Linda J. DeBowes, DVM, MS
Diplomate ACVIM (Internal Medicine), AVDC
Seattle, Washington


Periodontal disease refers to both gingivitis and periodontitis. This is a very common problem in dogs and cats and one that the veterinarian should be looking for on every oral examination that is done, AND… that should be done on every animal in your clinic!  


  • Infection and inflammation – the  “hallmarks” of periodontal disease  
  • Bacterial plaque and the host’s inflammatory both play a role in periodontal disease  


Basic anatomy of the tooth and supporting structures affected with periodontal disease  

  • Gingiva (marginal & attached)
  • Enamel & cementum
  • Cementoenamel junction (CEJ)
  • Gingival attachment
  • Gingival sulcus
  • Junctional epithelium
  • Alveolar bone
  • Periodontal ligament (PDL)
  • Periodontium (gingiva, cementum, PDL, alveolar bone)            
  • Salivary precipitates adhering to enamel
  • Bacteria bind to pellicle  

Plaque bacteria

  • Bind to pellicle
  • Accumulate at gingival margin
  • marginal gingivitis
  • Plaque bacteria accumulate & multiply
  • Plaque extends subgingivally
  • Increased gingival inflammation


  • Gingival attachment affected
  • Apical migration of junctional epithelium
  • Periodontal pocket formation
  • PDL destruction
  • Alveolar bone loss
  • Vertical and/or horizontal bone loss
  • Periodontal pocket depth increases
  • Gingival recession
  • Eventual tooth mobility and tooth loss


  • Inflammation of the gingiva
  • No loss of attachment
  • Reversible
  • May or may not progress to periodontitis if left untreated


  • Loss of attachment
  • Loss of junctional epithelium and gingival attachment
  • Destruction of PDL
  • Periodontal pockets
  • Alveolar bone loss
  • Gingival recession
  • Tooth mobility
  • Tooth loss
  • Quiet and active periods of inflammation

Clinical Signs  

  • Halitosis
  • Gingival bleeding
  • Oral discomfort/pain
  • Reluctance to chew
  • Lethargy, fever – severe periodontitis

Clinical importance of periodontal disease

  • Interactions with people
  • Oral comfort/discomfort
  • Systemic effects  

Oral examination

Initial examination – in an awake animal

  • Facial evaluation
  • Swellings
  • Facial asymmetry
  • Local lymph nodes
  • Occlusion
  • Teeth abnormalities/problems
  • Periodontal health
  • Oral soft tissues

Complete examination - with general anesthesia

  • Periodontal probe
  • Dental explorer
  • Dental x-rays  

Charting periodontal disease

Dental chart part of every medical record

Record exciting disease

  • Gingival index
  • Plaque & calculus
  • Furcation exposure
  • Attachment loss
  • Mobility

Record treatment done