Periodontal disease in dogsstages, symptoms, treatment and prevention

What periodontal disease in dogs is

The periodontium is the tooth’s “anchoring system”: the gums, the periodontal ligament that holds the root in its socket, and the alveolar bone. Periodontitis gradually destroys exactly these tissues.

It all starts with plaque — a bacterial film that forms on the teeth every day. The gums respond to it with inflammation — this is gingivitis. Part of the plaque mineralises and turns into tartar, which holds on to even more bacteria. Over time the bacteria get under the gum line, the inflammation spreads to the ligament and bone, a periodontal pocket forms and the gums recede.

Gingivitis is reversible: after professional cleaning and home care the gums can recover completely. Periodontitis is irreversible — lost bone does not grow back on its own, so the disease can be stopped and kept under control, but not “erased”.

Why periodontal disease develops and which dogs are at risk

The cause is plaque bacteria, but how fast the process goes also depends on the body’s response: with the same amount of plaque, inflammation develops differently in different dogs. The risk is higher with:

• small and toy breeds — Yorkshire terriers, Chihuahuas, toy poodles, dachshunds, Maltese, Pomeranians: there is little bone around the roots, so even a small loss of it noticeably weakens the tooth;
• brachycephaly (pugs, French bulldogs, Shih Tzus): the teeth are crowded and plaque gets trapped between them;
• retained baby (deciduous) teeth: sitting next to the permanent ones, they become a trap for plaque;
• age — changes build up over the years, although they often begin in young dogs;
• no daily brushing — dry food or treats do not replace a toothbrush.

Large dogs get periodontal disease too; the process is simply often noticed later. Breed is not a life sentence, and no breed is immune — it is a reason to start prevention earlier.

Stages of periodontal disease in dogs (AVDC classification)

Veterinary dentists assess each tooth separately using the AVDC scale (American Veterinary Dental College), according to how much of its attachment it has lost:

• PD0 — normal: the gums are pink and fit snugly around the tooth.
• PD1 — gingivitis: the gums are red and may bleed, but the bone is intact. This stage is reversible.
• PD2 — early periodontitis: less than 25 % of attachment lost. From the outside it looks like “gingivitis with tartar”; only a probe reveals the pocket.
• PD3 — moderate periodontitis: 25–50 % of attachment lost. An owner may notice receding gums and persistent bad breath.
• PD4 — advanced periodontitis: more than 50 % of attachment lost. An owner may see exposed roots, a loose tooth or pus.

Attachment loss is measured as a percentage of root length; in multi-rooted teeth furcation involvement also sets the stage: F1 — PD2, F2 — PD3, F3 (through-and-through) — PD4.

The stage is not judged by the amount of tartar: heavy tartar can sit over well-preserved bone, while an almost clean-looking tooth can have deep bone loss. That is why periodontal probing and dental X-rays under anaesthesia are needed. One dog usually has teeth at different stages, and the plan is made for each tooth separately.

Symptoms of periodontal disease in a dog: what an owner may notice

The early stages often go unnoticed. Be alert if you see:

• bad breath that does not go away;
• red gums, bleeding gums — blood on toys or in the bowl;
• tartar, especially on the canines and upper premolars;
• receding gums, with the root becoming visible;
• loose teeth or teeth that have fallen out;
• the dog chews on one side, drops food, refuses hard food, paws at its face;
• sneezing or discharge from one nostril — this may be an oronasal fistula next to an upper canine;
• facial swelling under the eye or on the cheek, a draining tract on the skin.

Why a dog keeps eating even though its teeth hurt

“But she’s eating normally” is something I hear all the time. Chronic pain builds up gradually and the dog adapts: it chews on the healthy side, swallows kibble whole, picks softer food. The urge to eat is stronger than the discomfort, and dogs are not inclined to show pain.

So I ask not “is the dog eating?” but “how exactly is it eating?”. Many owners only notice how much livelier their dog has become after treatment. More in the article why pets keep eating with painful teeth.

Why periodontal disease matters: not just the teeth

Periodontal disease means chronic inflammation and pain that last for years. In the professional literature it has been linked with changes in the kidneys, liver and heart: bacteria and inflammatory substances from the gums can enter the bloodstream and may affect other organs. These links are still being studied, but a constant source of infection in the mouth does the body no good.

Local complications:

• oronasal fistula — an opening between the mouth and the nose, typically next to an upper canine, with sneezing and nasal discharge. More in the article on oronasal fistula;
• pathological jaw fracture — in small dogs periodontitis can thin the bone around the roots of the lower molars so much that the jaw breaks under normal load;
• tooth-root abscess — purulent inflammation with swelling or a draining tract on the skin;
• eye problems — the roots of the upper back teeth lie close to the eye socket, so swelling under the eye is possible.

Diagnosis: consultation and COHAT under anaesthesia

At the consultation I can see the gums, tartar, loose teeth and any swelling — enough to suspect periodontal disease, but not to determine its stage. A full diagnosis is a COHAT under inhalational anaesthesia with monitoring. During it I:

• probe all the way around every tooth and measure the depth of the pockets;
• assess tooth mobility and the furcation;
• take full-mouth dental X-rays — images of every tooth;
• record everything on a dental chart, which forms the basis of the treatment plan.

None of this is possible without anaesthesia: probing pockets is painful, X-rays require the patient to be completely still, and cleaning under the gums means working with an instrument below the gum line. Teeth cleaning without anaesthesia gives the dog stress and the owner the illusion of clean teeth.

Before anaesthesia, blood tests are needed; echocardiography, abdominal ultrasound and other tests are added depending on age, health and examination findings.

Treatment of periodontal disease in dogs by stage

The aim is to remove plaque and tartar above and below the gum line, stop the inflammation and preserve teeth that still have enough support. The approach is chosen for each tooth separately:

Regenerative techniques make sense when the bone defect has a suitable shape and the owner is ready to brush the teeth every day and come for check-ups. An example is the case GTR and PRF to preserve a canine: it is about a cat, but the principle is the same.

Antibiotics do not treat periodontal disease on their own — they only supplement cleaning of the pockets if the vet considers them necessary.

Extractions frighten many owners, but dogs adapt well and often eat more willingly because the pain is gone — as in the case periodontal disease in a Yorkie. More on the periodontology page.

1. 01

   PD1 — gingivitis

   Professional cleaning above and below the gum line, polishing, then daily home care.

2. 02

   PD2 — early periodontitis

   Deep cleaning under the gums and smoothing of the root surface (root planing) so that the inflammation settles and the pocket becomes shallower.

3. 03

   PD3 — moderate periodontitis

   Closed treatment of the pockets, or open treatment by lifting a gum flap; in selected cases, regenerative therapy (GTR, bone graft) or extraction.

4. 04

   PD4 — advanced periodontitis

   Usually extraction: a tooth without support only sustains pain and infection. It is extracted under regional anaesthesia (nerve blocks), with post-extraction X-rays.

Care after treatment and prevention

Plaque starts to form again within hours of a cleaning and can begin to mineralise within a few days, so the result depends on home care: daily brushing with a soft toothbrush and veterinary, not human, toothpaste. How to get your dog used to it is explained in the article how to brush a dog’s teeth properly.

Products with the VOHC seal are a useful addition, not a replacement for the toothbrush. After surgical treatment, brushing starts when the vet allows it.

I plan check-ups individually, depending on the stage, the number of teeth preserved, the breed and how home care is going. More in how often a dog needs a dental check-up.

How much periodontal treatment for a dog costs

The cost is made up of the consultation, pre-anaesthetic tests, anaesthesia and the COHAT, whose price depends on the dog’s weight.

Myths about periodontal disease in dogs

“Bad breath in dogs is normal.” No. Persistent bad breath is a reason to have the gums checked.

“If the dog is eating, its teeth don’t hurt.” Dogs adapt to chronic pain and keep eating even at advanced stages.

“Dry food cleans the teeth.” Ordinary kibble barely cleans the gum line; dental diets only supplement brushing and do not treat periodontal disease.

“Tartar can be removed without anaesthesia and the problem is solved.” That is cosmetic: the inflammation under the gums remains, and a clean-looking crown hides the disease.

“A loose tooth will firm up by itself.” It is loose because it has lost bone, and bone does not regenerate on its own.

“Only old dogs get periodontal disease.” The first changes can appear in young dogs, especially in small breeds and dogs with retained baby (deciduous) teeth.

Frequently asked questions