Is Periodontal Disease Contagious in Dogs?

Poor dogs have been the butt of many jokes about bad breath. We know many dogs have stinky breath but dog owners rarely examine their dogs’ teeth and gums. Periodontal disease is extremely common in dogs. How does this happen and is periodontal disease contagious in dogs?

What Is Periodontal Disease?

Canine dental anatomy has many similarities to human dental anatomy. The main structures include the tooth and the periodontal tissues. The term periodontium refers to the tissues surrounding the tooth. The periodontium consists of the gums (gingiva), periodontal ligament, cementum and the bone immediately surrounding the tooth.

Periodontal disease happens when any disease process affects the periodontal tissues. Immune-mediated processes, infectious disease and oral cancer can all affect the periodontium.

White Maltese dog smiling (Is periodontal disease contagious in dogs?)
Small breed dogs are susceptible to periodontal disease but it’s not contagious.

How Do Dogs Get Periodontal Disease?

The most common cause of periodontal disease in dogs is the unmitigated build-up of bacterial plaque. Plaque is sort of a slime layer on teeth that forms when food particles interact with normal bacteria in a dog’s mouth. 

A thin layer of plaque is normal, but over time it thickens and allows anaerobic bacteria to grow. Minerals in saliva mix with the plaque to form hard calculus you might have seen on an adult dog’s teeth in the form of brown chunks sticking to the tooth. 

Scientists in veterinary medicine don’t fully understand how plaque leads to periodontal disease. But when there are more “bad” bacteria than “good” bacteria in the mouth the body can’t balance them and inflammation ensues. Inflammatory substances produced by the bacteria and the dog’s body build up and destroy the delicate tissues around the tooth. 

The interesting thing is some dogs can have a lot of plaque and ZERO periodontal disease. So the presence of plaque is not the only factor. Veterinarians believe genetics, general health and diet are important determinants in a dog’s oral health status.

Is Periodontal Disease Contagious in Dogs?

The most common kind of periodontal disease in dogs is not at all contagious. But the term periodontal disease refers to any disease of the tissues surrounding a tooth. So, technically, contagious disease could cause a periodontal tissue lesion. Again, this is very uncommon and would normally cause other symptoms.

Contagious causes of oral lesions in dogs include viral and bacterial infections including: 

  • Distemper virus
  • Viral warts
  • Transmissible venereal tumor
  • Tularemia

FIV, FeLV and calicivirus infections cause cat gum disease and stomatitis. Fortunately, these viruses do not infect dogs. 

Is Periodontal Disease Hereditary in Dogs?

Most veterinary dentists believe periodontal disease is caused by multiple factors, one of which is genetics. In general, small breed dogs are much more likely to have periodontitis than medium and large breed dogs. 

We need more scientific data to back up the idea that periodontal disease in dogs is hereditary. However, a 2015 study did find a correlation between the presence of certain genes and the likelihood of a dog having periodontal disease. (1)

Dog Periodontal Disease Symptoms

Many dog owners are unaware that their dogs have any dental problems. Some symptoms are easy to see, but others can only be detected with radiographs and an anesthetized dental exam. 

Symptoms of diseased teeth and gums that you can watch for at home: 

  • Bad breath
  • Oral pain
  • Hesitance to eat or only wanting soft food
  • Dropping food while trying to eat
  • Chewing strangely or on one side only
  • Crying out while playing with a chew toy
  • Bleeding gums
  • Facial swelling
  • Recessed gums
  • Pus seen at the gumline
  • Loose teeth
  • Missing teeth

Just because you don’t see any of these symptoms does not mean your dog has a healthy mouth. You would be shocked at how many problems are identified when vets take oral radiographs and probe around a dog’s teeth when they’re anesthetized. 

Periodontal Disease in Dogs Stages

Veterinarians have a system they use to describe the severity of dog periodontal disease. Periodontal disease stages in dogs can only be determined when a dog is under anesthesia to allow a detailed dental exam. 

Stage 0: gum tissue and deep periodontal anatomy are all normal. 

Stage 1: inflamed gums but no loss of periodontal tissue attachment to the tooth

Stage 2: 1-25% loss of tissue attachment to the tooth

Stage 3: 26-50% loss of tissue attachment to the tooth

Stage 4: 51-99% loss of tissue attachment to the tooth

How to Treat Periodontal Disease in Dogs

The bad news is that periodontal disease is not reversible. Once the tissues have become inflamed and detached from the tooth, the only strategy is to stop the progression of the disease. 

The first step in stopping periodontal disease is to identify all the diseased tissues, including tooth root abscesses and bone loss. Tooth extraction is often the best option to treat severely compromised teeth. 

Your vet will also perform a dental cleaning to remove plaque and calculus from the tooth surface above and below the gum line. They may apply antibiotics and other therapeutics to help viable tissues return to health. 

The next part is just as important: ongoing home care of your dog’s teeth. Daily tooth brushing is the mainstay of preventing the progression of periodontal disease. Your veterinarian might recommend some additional steps to take including water additives and special treats to help control oral plaque.

How to Prevent Periodontal Disease in Dogs 

The best way to prevent periodontal disease is by brushing your dog’s teeth every day. Brushing daily breaks up the soft, thin layer of plaque that is always forming on a dog’s teeth. Plaque starts to turn into hard calculus within a few days. 

Many of my clients think that having the groomer brush their dog’s teeth every 3 months or so is adequate. It’s not! You have to do it every day to see the most benefits. 

Brushing your dog’s teeth daily also gets you in the habit of looking for oral problems like loose teeth and inflamed gums. 

Make sure to have your veterinarian look at your dog’s mouth once or twice a year, too. If they recommend a dental cleaning, do it! Even if the crowns of the teeth look pretty good, there can be serious problems lurking below the gumline. 

The excuse that anesthesia is too dangerous is unfounded. Unless your dog suffers from a very serious systemic disease, your vet can design a safe anesthesia protocol for their dental procedure. 

If you want to be extra cautious, ask for a referral to a veterinary dental specialist. It will cost more, but these super-vets are used to dealing with tough cases and fragile dogs. 

How Long Can Dogs Live with Periodontal Disease?

Periodontal disease is not a common cause of death. Many dogs live years with periodontal disease. Most of the time, when a dog loses all of their teeth and the disease is somewhat interrupted. That’s not to say they can’t have ongoing problems in their mouths. 

Periodontal disease can make other diseases worse. The constant inflammation and presence of bad bacteria may contribute to heart, liver and kidney disease. (2) Oral pain can also make a dog eat less so they can’t fight infectious diseases as well.  


The most common cause of periodontal disease in dogs is plaque. The bacteria that cause plaque and periodontal disease are not contagious between dogs or between dogs and humans. 

There are a few rare contagious causes of inflammation of a dog’s periodontal tissues. Dogs affected by contagious diseases almost always have other symptoms besides inflamed oral tissues. provides content for informational and entertainment purposes. You should always seek care from a veterinarian to diagnose and treat your unique pet. Visit the Privacy Policy and Terms of Use section of this site to learn more.

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  1. Albuquerque, C., Morinha, F., Magalhães, J., Requicha, J., Dias, I., Guedes-Pinto, H., … & Viegas, C. (2015). Variants in the interleukin-1 alpha and beta genes, and the risk for periodontal disease in dogs. Journal of genetics, 94(4), 651-659.
  2. DeBowes, L. J., Mosier, D., Logan, E., Harvey, C. E., Lowry, S., & Richardson, D. C. (1996). Association of periodontal disease and histologic lesions in multiple organs from 45 dogs. Journal of veterinary dentistry, 13(2), 57-60.
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