What Are the Grades of Canine Dental Disease?

by Christina Stephens
    These pearly whites are proud to be ungraded!

    These pearly whites are proud to be ungraded!

    Chris Amaral/Digital Vision/Getty Images

    It’s important to properly care for your buddy’s chompers. According to the American Veterinary Dental Society, more than 80 percent of dogs will develop periodontal disease, the most common form of canine dental disease, by the age of 3. Veterinarians categorize the severity of periodontal disease in grades from mild to severe.

    Understanding Periodontal Disease

    "Periodontal disease" is a broad term used to describe inflammation and/or infection of the gums and other tissues that surround your dog’s teeth. The disease occurs when bacteria accumulates in his mouth and forms plaque. Plaque eventually hardens into calculus, commonly known as tartar, and adheres to his teeth. If left untreated, plaque spreads underneath the gum line and eventually damages the gums and soft tissue as well as the tooth itself.

    Grade One

    Grade one, or mild, periodontal disease is characterized by slightly inflamed, swollen red gums and a light coating of white or yellow tartar on one or more teeth. Veterinary dental cleaning and regular oral care at home can treat and reverse periodontal disease at this early stage.

    Grade Two

    Grade two is moderate disease with characteristic reddened, inflamed gums that may bleed when probed, gum recession, increased plaque accumulation and the onset of bad breath. You may notice a thin red line where your dog’s teeth meet the gums.

    Grade Three

    Severe periodontal disease is labeled grade three. At this point your dog may be in noticeable pain and have trouble chewing his food. Thick tartar covers his teeth, and his gums are cherry-red and swollen. Internally, bacteria weaken his teeth, ligaments and even jaw, while bad breath is ever-present externally. Professional cleaning within the next 30 days is imperative at this stage.

    Grade Four

    Grade four, the most advanced stage of periodontal disease, presents as bloody gums often with open ulcerations or sores, pus along the gum line and severe tartar and plaque. At this stage, bacteria from your dog’s mouth are spreading throughout his body via the bloodstream, leading to illness, infection and even organ failure. Dogs diagnosed with grade-four periodontal disease often lose some, many or all of their teeth from damage.


    Start brushing your buddy’s teeth with a soft-bristled brush and canine-safe toothpaste when he’s a puppy, and continue that oral care routine throughout his life to maintain healthy teeth and gums. Veterinarians also recommend avoiding soft, sticky diets to prevent periodontal disease. Instead, feed your dog nutritionally balanced dry food and allow the chewing action to help scrub his teeth clean. Small or toy breeds such as Yorkshire terriers and toy poodles, as well as brachycephalic ("short-headed") breeds like pugs and Boston terriers are at greater risk for developing periodontal disease due to their crowded teeth. Regular dental checkups with your veterinarian are important for all dogs, but extra vigilance is required for owners of these predisposed breeds.

    Photo Credits

    • Chris Amaral/Digital Vision/Getty Images

    About the Author

    Christina Stephens is a writer from Portland, Ore. whose main areas of focus are pets and animals, travel and literature. A veterinary assistant, she taught English in South Korea and holds a BA in English with cum laude honors from Portland State University.

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