Dental Disease in Dogs: Stages, Signs and Treatment

By Tailwisp Editorial TeamUpdated October 17, 20264 min read

Few health problems are as widespread in dogs as dental disease, and few go unnoticed for as long. Most owners only realize something is wrong when a dog's breath becomes unpleasant, a tooth breaks or the dog quietly stops chewing on one side. By then, the disease is usually well established. Understanding how it develops makes it far easier to prevent.

What dental disease actually is

Dental disease, formally called periodontal disease, is inflammation and infection of the structures that support the teeth: the gums, the ligament that anchors each tooth and the bone beneath. It begins with plaque, a soft film of bacteria that forms on teeth within hours of eating. If plaque is not removed, minerals in saliva harden it into tartar (also called calculus) within a few days. Tartar is rough, which attracts more plaque, and it pushes bacteria below the gumline, where the real damage happens.

The four stages

Veterinarians commonly grade periodontal disease in four stages.

1. Stage 1: gingivitis. The gums look red and slightly swollen along the edge of the teeth. There is no bone loss. This stage is fully reversible.
2. Stage 2: early periodontitis. Pockets begin to form around the teeth, and up to a quarter of the supporting attachment is lost. X-rays may show early bone changes.
3. Stage 3: moderate periodontitis. Between a quarter and a half of the tooth's support is lost. Gums recede, teeth may loosen and infection is established.
4. Stage 4: advanced periodontitis. More than half of the support is gone. Teeth are loose or painful and often need extraction.

Because most of the disease sits beneath the gumline, a tooth that looks only mildly dirty can have serious problems below the surface. That is why X-rays are central to proper dental care.

Warning signs to look for

Dogs are experts at hiding pain, so signs can be subtle.

• Persistent bad breath, especially a rotten or sour smell
• Yellow or brown crusting on the teeth, particularly the back molars
• Red, swollen or bleeding gums
• Drooling more than usual, sometimes with blood
• Dropping food, chewing on one side or reluctance to chew hard food or toys
• Pawing at the mouth or face-rubbing
• Loose, broken or missing teeth
• Swelling under an eye, which can indicate a tooth root abscess

A dog that is suddenly head-shy, irritable or off its food may be in dental pain. If you see any of these signs, book a veterinary exam rather than waiting.

Why dental disease matters beyond the mouth

Chronic oral infection is more than a cosmetic problem. It is painful, and bacteria from the mouth can enter the bloodstream. Veterinary literature associates severe periodontal disease with strain on organs such as the heart, liver and kidneys, although the exact relationships are still being studied. Advanced disease can also erode the bone of the jaw, leading to fractures in small breeds and to oral-nasal fistulas, openings between the mouth and nose that cause sneezing and nasal discharge.

Which dogs are most at risk

• Small and toy breeds. Crowded teeth in small jaws trap plaque, and these breeds often develop disease younger.
• Flat-faced breeds. Their teeth are often rotated and tightly packed.
• Dogs with soft or sticky diets. Diet is only one factor, but dogs who never chew anything abrasive may accumulate tartar faster.
• Older dogs. Years of accumulated plaque take their toll.
• Dogs with genetic predisposition. Some individuals form tartar quickly regardless of care.

How vets diagnose and treat it

A vet will examine the mouth awake, but a full assessment needs a general anesthetic. Under anesthesia the team will:

• Take dental X-rays to see roots and bone.
• Measure pocket depths with a probe.
• Scale tartar above and below the gumline with ultrasonic and hand instruments.
• Polish the teeth to smooth the surface.
• Extract teeth that are badly diseased or loose.
• Apply local anesthesia to the area and send your dog home with pain relief and, if needed, antibiotics.

Recovery is usually quick. Many dogs feel noticeably better, eating more comfortably and showing more energy, once painful teeth are dealt with. For more on the procedure, see our guide to teeth cleaning at the vet.

Preventing dental disease at home

Home care is the single best way to slow plaque and tartar buildup.

• Brush daily if you can. It is the gold standard. Use a pet toothpaste, never human toothpaste, and build up gradually. See our step-by-step guide to brushing a dog's teeth.
• Choose products with a quality seal. The Veterinary Oral Health Council evaluates dental chews, diets and water additives for plaque and tartar control.
• Offer safe chews. Avoid very hard items like real bones, antlers and hard nylon, which can fracture teeth. A good rule of thumb: if you cannot dent it with a thumbnail, it may be too hard.
• Schedule regular checkups. Many vets advise a dental check at every annual exam and professional cleanings as recommended for your individual dog.

When to see the vet urgently

Contact your veterinarian promptly if you notice facial swelling, bleeding from the mouth, a broken tooth with exposed pink or red tissue, inability to eat or a foul discharge from the nose. These can signal an abscess or fracture that needs treatment.

The bottom line

Dental disease is common, painful and preventable. A few minutes of daily care and regular veterinary checks can protect your dog's teeth, comfort and overall health. If your dog's breath has become unpleasant, treat it as a clue rather than a quirk, and have the mouth examined. For a deeper look at smells, read about why dogs have bad breath.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.