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Dog Tooth Decay Stages And Dental Disease: How To Save Your Dog - PawSafe
Dog Dental

Dog Tooth Decay Stages And Dental Disease: How To Save Your Dog

Photo of Tamsin De La Harpe

Written by Tamsin De La Harpe

Dog Dental Disease Stages of Tooth Decay

Inflammation and decay in your dog’s gums and teeth can cause heart problems and diabetes. So it’s vital to recognize the stages of dog tooth decay and disease.

The various dog tooth decay stages and dental disease (periodontitis) progression pose a significant but often ignored health risk to our pets. In fact, periodontitis is the seventh most common health issue facing our beloved canine companions. What’s worse, gingivitis, periodontal disease, and rotting teeth in dogs are not only a source of pain and discomfort but also lead to various long-term health conditions, including diabetes and heart issues.

While periodontal disease in dogs is widespread, cavities are quite rare. About 80% of dogs will suffer from periodontitis by the time they are two years old, but only 5% will actually get a cavity.

This is because dogs don’t have flat teeth like ours, where food is more likely to get stuck. Nevertheless, both periodontitis and cavities threaten our pet’s well-being, and each has its own stages. So let’s look at the progression of canine gum disease and tooth cavities.

Dog Tooth Decay Stages: What Is Periodontitis In Dogs?

Dental or periodontal disease in dogs is inflammation of the periodontium. These are all the tissues that support the teeth and keep them in place, including the:

  • Gums (gingiva),
  • Periodontal ligament (PDL), which is a fibrous joint that locks the tooth into the jawbone,
  • Cementum or out layer of the tooth’s root that is attached to the PDL,
  • And the Alveolar bone or bone socket the tooth fits into that is also attached to the PDL.

Gum disease is hard to spot until the final stages, which means it is also one of the most undertreated ailments. When dog owners notice the problem, it may be too late. This is why it is crucial to invest in an excellent dental rinse for dogs that you can add to their water, or be sure to brush teeth daily. Make sure to book your dog for regular professional dental cleanings from your vet as well.

Periodontitis is also far more serious than simply inflammation in the tissue around the tooth and bad breath. Bad bacteria that cause inflammation in the mouth can cause the bone to lose density, resulting in jaw fractures. Chronic inflammation and harmful bacteria can spread throughout the body, leading to heart disease, eye issues, cancers, diabetes, kidney problems, and even contribute to doggy dementia.

The bad bacteria disrupt the healthy microbiome in the mouth and spreads to the gut, causing leaky gut syndrome and inflammation. It can even lead to fatal sepsis.

What Causes Periodontal Disease in Dogs?

The disease starts with the build-up of plaque on the teeth. This happens when specific glycoproteins in a dog’s saliva get stuck to their teeth. Certain bad bacteria colonize these glycoproteins and release acidic sugary by-products. This acidity attacks the protective mucosal lining around the gums, making gaps that the bacteria can “leak” through. The bad bacteria also excrete cytotoxins and endotoxins that make the inflammation worse.

Once the bacteria has passed through the tiny holes, they infect the tissue, starting with the gums. This causes the gums to become red, swollen, and inflamed. At this stage, it is still gingivitis, or inflammation of the gums and you can still prevent periodontal disease.

When the problem spreads to ligaments and bone tissue holding the tooth, it becomes periodontitis. At this stage, the damage is irreversible, but you can take steps to slow the progression.

Plaque also calcifies and becomes tartar or calculus. Together, plaque and tartar make the perfect environment for more harmful bacteria, leading to a build-up. As plaque and tartar build on the teeth, so do the number of harmful bacteria that cause inflammation and infection.

What makes these bacteria even worse is that they are resistant to antibiotics and cause an immune response. When the white blood cells attack the bacteria and die, they release enzymes. These enzymes cause even more damage to vulnerable tissue around the teeth and even more inflammation. In fact, the stronger a dog’s immune response is to the infection, the faster the disease will actually spread. That said, dogs with a weak immune system, diabetes, and even stress tend to have worse teeth than healthy dogs. They can also suffer from tooth abscesses and oronasal fistulas.

For this reason, the best dog food for dental issues should be anti-inflammatory. This means plenty of omega-3 fatty acids from fish and marine sources and less omega-6 or saturated fats. It should also be high in lean, quality, white meat protein, a few whole grains, and plenty of antioxidants, such as vitamin E. Probiotic strains such as L.Salivarius can also help prevent plaque.

The best dog toothpaste and best products for dog teeth will also often contain Sodium hexametaphosphate (HMP), which naturally stops calcium from mineralizing plaque and causing tartar.

Note that your dog’s breed also plays a role, with short-nosed (brachycephalic) breeds such as pugs and bulldogs generally having poorer oral health and need more dental care. A small dog breed such as a Maltese can also have an overcrowded mouth that needs regular veterinary dental check-ups about every six months.

What Are The Stages Of Doggy Dental Disease?

Stage 1: Gingivitis

The first stage of this disease is gingivitis or inflammation of the gums. All the acids and toxins from the virulent bacteria and the enzymes from the dead white blood cells damage the delicate gum tissue. Here you may notice a red line along the top of the gums.

At this stage, the intervention can still make the disease reversible and prevent further dental problems. Your vet can give your dog a professional teeth cleaning to remove the plaque under the gum lining. A good dental hygiene regimen can prevent the problem from growing bigger.

Stage 2: Early Periodontal Disease

In the second stage, the ligaments that hold the tooth in place are affected. So the tooth is no longer secured in the socket and has lost up to 25% PD attachment. At this stage, a dog needs an X-ray to establish the extent of the damage, as there may be some loss in the bone density surrounding the tooth.

A vet will need to scale the teeth under the gums and polish them to help prevent plaque in the future. They may also apply an antimicrobial treatment.

Stage 3: Established Periodontal Disease

The dog has lost between 25 and 50% attachment at this stage. This means the structures around the teeth, such as the PD ligaments and the alveolar bone, are infected and damaged.

The vet may need to do open or closed root planing and treat the bacterial infection. They may also need to start advanced periodontal treatment. At this point, your dog is likely in a lot of pain, and the damage is not reversible. Extensive visible tartar and bad breath will be the most obvious symptom.

You can read more about why your dog may have bad breath in this article or why your dog may have fishy breath here.

Stage 4: Advanced Periodontal Disease

In the final stage, there is over 50% attachment loss, with significant damage to the supporting ligaments, gums, and bone around the tooth. At this stage, the infection is likely to spread to other parts of the body and create multiple issues related to chronic inflammation. The bone can be so weakened that your dog may suffer a jaw fracture and is likely to need one or more teeth extracted.

Dog periodontal disease stage 4 treatment often involves full-blown periodontal surgery. Maintaining dental hygiene at home can slow the disease progression, but much of the damage is already done.

Periodontitis vs. Decaying Teeth In Dogs

Although periodontitis and tooth cavities in dogs overlap, they are not quite the same thing. Of course, they both start with plaque. But while canine periodontitis infects the tissue around the tooth, a cavity is where the plaque eats away at the tooth’s protective enamel and damages the tooth itself.

Cavities or caries can happen where teeth grow too close together, where teeth are worn down, or at the bottom of the tooth if the gum has receded. It also happens to the grooves at the top of the molars, similar to human teeth. Cavities can look like:

  • A dull gray or brown spot where one is just starting
  • A hollow or hole in the tooth with a black or dark surface.

If your dog has bad teeth and gums, it’s important to recognize the stages of dog teeth in the process of decay. Beware of dog tooth decay home remedies, as the best cure is prevention, and actual dental decay will also need veterinary attention.

Stages Of Decaying Teeth

Stage one:

In the first stage, only the outer layer of the tooth, the enamel, is affected. It’s important to examine your dog’s mouth regularly as you may notice a gray spot where the enamel is wearing away.

Stage two:

The acidic by-products from the bad bacteria in the dog’s mouth have demineralized the enamel. They have started rotting the dentin below it.

Stage three:

The rot spreads through the enamel, the dentin layer, and reaches the sensitive pulp inside the tooth. At this point, your dog will feel pain and show signs of struggling to eat.

Stage four:

In the fourth stage, the rot has eaten so much of the tooth that the crown’s structure is damaged.

Stage five:

In the fifth stage, the dog has lost much of the visible portion of the tooth, and the sensitive root below is exposed. This is extremely painful, and a vet will need to extract whatever is left of the tooth.

What should I do if my dog’s teeth are rotting?

If your dog has rotting teeth, they need veterinary attention. As soon as teeth have gotten as far as decay and rot, there is no longer anything you can do to reverse the problem. Tooth decay treatment usually involves removing the bad teeth.

Sometimes, a veterinary specialist cleans out and fills the cavities and even performs root canals to save the tooth. However, it is then up to you to maintain a strict dental health regime to prevent further tooth damage. You can read more about how to clean your dog’s mouth in this article.

Signs of oral disease and rotting teeth in dogs

  • Halitosis or bad breath
  • Flinching, growling, snapping, or pulling away if you touch the mouth area
  • Trembling lips
  • Inflamed, angry red gums instead of healthy pink gums
  • Visible tartar or plaque
  • Discolored teeth
  • Bleeding or swelling from or around the mouth
  • Receding gums that let you see the bulge of the tooth’s crown or the roots.
  • Wounds under the eye, lower jaw, inside or around the mouth
  • Ulcers around the mouth area
  • Rubbing the face against the objects or pawing the mouth
  • Lethargy, sleeping more than usual,
  • Refusing food or reluctant to eat.
  • Dropping food or treats
  • Chewing abnormally.

Frequently Asked Questions (FAQs)

How long can dogs live with periodontal disease?

There is no set timeline for how long dogs can live with periodontitis. However, it generally causes complications that can shorten your dog’s life, usually by roughly two years. The problem is that periodontal disease can directly or indirectly cause serious health complications such as kidney or heart disease or even a fatal case of sepsis.

How fast does dental disease progress in dogs?

Plaque can cause gingivitis within four weeks after a pet parent stops cleaning their pet’s teeth. Most dogs who don’t receive dental care within six months will have some periodontitis. The speed at which it progresses depends on a dog’s immune system. The more active the immune response, the faster the disease will grow.

Final Thoughts

Periodontal disease is perhaps the biggest and most untreated problem in dogs. Frequently, owners complain about their dog’s bad breath without realizing the severe health risk bad teeth pose to the dog’s health and longevity. It is vital to take care of our dental from the time they are puppies and to be aware of the stages of both decay and gum disease.


Niemiec, Brook A. “Periodontal disease.” Topics in companion animal medicine 23.2 (2008): 72-80.

Wallis, C., & Holcombe, L. J. (2020). A review of the frequency and impact of periodontal disease in dogs. Journal of Small Animal Practice, 61(9), 529-540.

Meet Your Experts

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Tamsin De La Harpe


Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.

Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.