What are periodontal disease stages (grades 1-4)?
A four-grade veterinary classification system that categorizes the severity of periodontal disease in pets, from mild gum inflammation to severe bone loss, guiding treatment decisions.
Periodontal disease in pets progresses through four clinically distinct stages, each reflecting increasing damage to the gums, tooth attachment, and underlying bone. Veterinarians use this grading system to assess disease severity and determine what treatment a patient needs.
Grade 1 involves gingivitis, the earliest stage marked by gum inflammation and minor plaque and tartar buildup. The tooth structure remains intact, and the condition is reversible with professional cleaning and improved home care. Grade 2 shows early periodontitis with up to 25 percent bone loss around the tooth roots. The gum line begins to recede, and plaque extends below the surface. Grade 3 represents moderate periodontitis with 25 to 50 percent bone loss. Teeth become loose, pockets deepen, and extraction may be necessary for severely affected teeth. Grade 4 is advanced periodontitis, involving more than 50 percent bone loss. Teeth are highly mobile, root exposure occurs, and extraction is typically the only viable option to relieve pain and prevent infection spread.
Knowing a pet's periodontal grade helps veterinarians explain what is happening, what complications to watch for, and whether scaling alone or tooth extraction is needed. Early detection through regular oral exams and grading allows for more conservative treatment. When you visit a dental-focused veterinary practice in Denver, the veterinarian will grade any disease present to develop a specific treatment plan.