CONDITION

Periodontal Disease

Periodontal disease describes the progressive damage to the structures that hold teeth in place — the gums, the ligament that anchors each tooth, and the bone of the jaw itself. It begins with plaque, a soft film of bacteria that forms on the tooth surface within hours of eating. If plaque is not removed, it mineralises into tartar, and the bacteria beneath trigger inflammation that can eventually erode bone and loosen teeth. Many owners first notice a change in breath odour, reluctance to eat hard food, or a visible brown crust along the gum line. Some dogs and cats show no outward sign at all, even when disease beneath the gum is well established. The condition is extremely common — surveys suggest that most dogs and cats over the age of three have some degree of periodontal change — but the rate of progression and the severity vary widely between individuals. This page explores what periodontal disease looks like from the outside, what is happening beneath the gum line, how the extent of damage is assessed, and the range of approaches used to slow progression or manage established disease. It also covers the role of home care, professional cleaning under anaesthesia, and the products that have been evaluated by the Veterinary Oral Health Council for their effect on plaque and tartar.

Why this matters now

Periodontal disease affects the vast majority of dogs and cats by three years of age, making it one of the most prevalent health conditions in companion animals. The condition develops progressively, often beginning silently in young adulthood and advancing throughout life. Certain breeds with crowded teeth or flat faces may experience earlier or more severe involvement.

The condition typically begins with plaque accumulation along the gum line, progressing to tartar formation, gum inflammation (gingivitis), and eventually periodontal disease affecting the supporting structures of teeth. As the disease advances, bone loss around tooth roots can occur, potentially leading to tooth loosening or loss. Bacteria from the mouth may enter the bloodstream, with research suggesting possible associations with heart, kidney, and liver health.

Signals & patterns

Early signals

Mild bad breath

A subtle change in breath odour often represents the earliest noticeable sign, as bacterial populations in the mouth begin to increase.

Slightly reddened gum margins

A thin red line along the gum edge, particularly around the back teeth, may indicate early gingivitis.

Visible yellowish deposits on teeth

Tartar accumulation typically begins on the outer surfaces of the upper back teeth and canines.

Occasional pawing at the mouth

Pets may intermittently touch their face or mouth, suggesting early discomfort.

Later signals

Strong, unpleasant breath odour

Advanced periodontal disease produces a characteristic foul smell from bacterial activity and tissue breakdown.

Reluctance to eat or preference for softer foods

Pain when chewing may lead to changes in eating behaviour, though many pets continue eating despite significant dental disease.

Visibly receding gums or exposed tooth roots

Loss of supporting tissue causes gums to pull back from teeth, sometimes revealing root surfaces.

Loose teeth or changes in bite alignment

Bone loss around roots can cause teeth to become mobile or shift position.

Click to read about the biological mechanisms

How this is usually investigated

Diagnosis typically begins with a visual assessment of the mouth, looking at gum colour, tartar deposits, and any obvious swelling or recession. A dental assessment under general anaesthesia allows closer examination of individual teeth, measurement of pocket depths around each tooth, and visualisation of areas hidden by the tongue or cheeks. Radiography of the teeth and jaw may be used to assess bone loss and changes beneath the gum line that are not visible externally.

Physical examination

Purpose: The conscious examination provides an initial view of visible tartar, gum inflammation, broken teeth, and oral masses. It can reveal obvious asymmetry, drooling, or reluctance when the mouth is handled.
Considerations: Many dogs and cats will not tolerate thorough manipulation of the lips and gums whilst awake, and the back teeth often cannot be seen clearly. What is visible on the surface does not reliably predict the severity of bone loss or deep pocket formation.

Dental assessment

Purpose: Assessment under general anaesthesia permits probing around each tooth to measure pocket depth, assess tooth mobility, and examine surfaces that cannot be reached in the conscious patient. A dental chart is typically created, recording findings for each tooth.
Considerations: This requires anaesthesia, which carries its own considerations, particularly in older patients or those with concurrent health conditions. The assessment informs decisions about which teeth may require extraction or other intervention.

Radiography

Purpose: Dental radiographs reveal bone levels around tooth roots, the presence of root abscesses, retained root fragments, and other changes beneath the gum line. They can show bone loss that is not apparent from surface examination alone.
Considerations: Radiography adds time and cost to a dental procedure and requires specific positioning and technique. The images provide important information for treatment planning, particularly when deciding whether a tooth can be retained or should be removed.

Complete blood count

Purpose: A blood count may be performed before anaesthesia to screen for conditions such as anaemia or changes in white blood cell populations that could affect anaesthetic risk or healing.
Considerations: This is part of pre-anaesthetic assessment rather than specific to periodontal disease itself. Normal results do not guarantee absence of other health concerns, and mild abnormalities may still allow anaesthesia to proceed with appropriate precautions.

Chemistry panel

Purpose: A chemistry panel evaluates organ function, particularly kidney and liver parameters, which inform anaesthetic protocol choices and highlight any systemic conditions that may influence healing or treatment decisions.
Considerations: Abnormalities may be unrelated to dental disease, though chronic inflammation can sometimes be associated with changes in organ function. Results help tailor the anaesthetic approach and may prompt additional monitoring or medication adjustments.

Options & trade-offs

Management usually combines approaches aimed at removing existing bacterial load, reducing ongoing accumulation, and addressing discomfort or infection. The combination that proves workable varies with the severity of disease, the temperament and health of the individual animal, and what an owner can sustain over time. Different households find different strategies more or less practical.

Professional dental cleaning and treatment

Scaling removes tartar from tooth surfaces and beneath the gum line, followed by polishing to smooth enamel. Diseased teeth may be extracted if bone loss or mobility makes retention unviable. The procedure is performed under general anaesthesia to allow thorough cleaning and assessment of all surfaces.

Trade-offs: Anaesthesia carries inherent risks, particularly in older animals or those with heart, kidney, or other systemic conditions, though these can often be managed with appropriate monitoring and protocol adjustments. The procedure addresses existing disease but does not prevent recurrence without ongoing home care or other preventive measures.

Home oral hygiene

Daily tooth brushing with a soft brush and veterinary toothpaste can reduce plaque accumulation before it mineralises into tartar. The focus is on the gum line where bacteria tend to collect. Success depends on the animal's tolerance and the owner's ability to maintain a routine.

Trade-offs: Many cats and some dogs do not tolerate brushing, and attempts to introduce it can create stress or damage the bond between owner and pet if not approached gradually. Even with diligent brushing, some individuals develop tartar more readily than others, and brushing alone may not prevent disease in animals with advanced or rapidly progressing involvement.

Dental diets and water additives

Specially formulated dental diets have a texture or coating designed to reduce plaque or tartar as the animal chews. Water additives contain compounds intended to alter the oral environment or interfere with plaque formation. Some products carry Veterinary Oral Health Council (VOHC) acceptance, indicating they have been shown in controlled trials to reduce plaque or tartar.

Trade-offs: The degree of effect varies between products and individuals, and these approaches typically work alongside rather than replacing other measures. Switching diet may not be suitable for animals with specific nutritional needs, food sensitivities, or strong preferences, and some pets dislike the taste of water additives.

Dental chews and toys

Chew items with specific textures or shapes can provide mechanical cleaning as the animal gnaws, potentially reducing plaque on chewing surfaces. Products with VOHC acceptance have demonstrated measurable effects in controlled studies.

Trade-offs: The benefit depends on how much and how the animal chews, and some dogs or cats show little interest or swallow pieces without prolonged chewing. Hard chews carry a risk of tooth fracture, particularly in animals with weakened or already compromised teeth, and supervision is often warranted.

Antibiotics and anti-inflammatory medication

Antibiotics may be used when there is evidence of active infection, such as a tooth root abscess or severe gingival inflammation with discharge. Anti-inflammatory drugs can reduce pain and swelling in the short term, particularly around procedures or when extractions have been performed.

Trade-offs: These medications address symptoms or secondary infection but do not remove the underlying bacterial load or reverse structural damage such as bone loss. Long-term or repeated antibiotic use can contribute to resistance, and anti-inflammatory drugs carry their own side-effect profile, particularly with prolonged use or in animals with kidney or gastrointestinal sensitivities.

Common misconceptions

Misconception:

"Bad breath is normal in older dogs and cats and does not indicate a health problem."

Reality:

Whilst many older animals do have noticeable breath odour, this typically reflects bacterial activity associated with periodontal disease rather than an inevitable aspect of ageing. The odour often signals ongoing inflammation and infection that may warrant investigation and treatment.

Misconception:

"If a dog or cat is still eating normally, their teeth must be fine."

Reality:

Many animals continue to eat despite significant periodontal disease, fractured teeth, or oral pain. Dogs and cats often adapt their chewing behaviour, swallow food with minimal chewing, or preferentially use one side of the mouth. A normal appetite does not rule out the presence of painful or progressing dental disease.

Misconception:

"Once tartar is removed, the teeth will stay clean without further intervention."

Reality:

Professional cleaning removes existing tartar and treats diseased tissue, but plaque begins to form again within hours. Without ongoing home care, dietary measures, or other preventive strategies, tartar typically reaccumulates, and the disease process can resume. The interval before repeat cleaning is needed varies widely between individuals.

Related conditions

Tooth Resorption

Tooth resorption and periodontal disease can both affect the same tooth at different points, and severe periodontal disease may sometimes mimic or mask early resorptive lesions. Both conditions involve progressive damage beneath the gum line that may not be fully visible on the surface.

Stomatitis in Cats

Stomatitis and periodontal disease both involve chronic inflammation affecting the gums and other structures in the mouth, though stomatitis tends to be more widespread and severe. In some cats, periodontal disease may coexist with or contribute to the inflammatory burden seen in stomatitis.

Oral Squamous Cell Carcinoma in Cats

Oral squamous cell carcinoma can present with visible changes to the gums or jaw that may initially be mistaken for advanced periodontal disease, particularly when there is bone involvement or tooth loosening. Both conditions can cause similar outward signs, and in some cases they may be present together.

Endocarditis

Bacteria from periodontal disease can enter the bloodstream through inflamed or damaged gum tissue, and in some cases this may seed infection on the heart valves, contributing to endocarditis. The relationship reflects a pathway rather than a certainty, and many other sources of bacteraemia exist.

Hepatic Lipidosis in Cats

Cats with severe periodontal disease may experience enough oral discomfort to reduce their food intake, and in some cases this reduced appetite can contribute to the cascade that leads to hepatic lipidosis. The connection is indirect and depends on other factors, including the cat's body condition and underlying health.

Periodontal disease often develops alongside other age-related changes, and patterns of inflammation or organ function may shift over time. Understanding how oral health intersects with broader questions of longevity and healthspan can provide context for decisions made at different life stages. Observations about eating behaviour, breath, or changes in the mouth can form part of a wider conversation about maintaining comfort and function as an animal ages.

Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS