Dog Periodontal Disease and Tooth Brushing: The "80%" Number, and How to Keep Up With Care

Last updated: August 15, 2026

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The figure "80% of dogs over 3 have periodontal disease" doesn't appear in the paper it's usually credited to. The clinical-records-based rate is just over 10%, but the number shifts a lot depending on how it's checked — some reports find it higher the more closely you look. More reliable than the number itself is the finding that brushing daily to every other day helps.

  • The paper usually credited as the source of "80%" doesn't contain that figure
  • The clinical-records-based rate is just over 10% — but it moves a lot depending on how it's checked
  • A study found daily-to-every-other-day brushing clearly reduced plaque, tartar, and gingivitis
  • Tartar that's already formed can't be removed at home. Veterinary specialist bodies in Japan and elsewhere don't recommend anesthesia-free tartar removal (why)

"80% of dogs over 3 have periodontal disease" — a line you'll often see in pet product write-ups and articles. The state of teeth and gums often can't be judged by looking alone. If you notice anything concerning, see a vet before relying on anything written here.

① The "80%" figure doesn't appear in the paper it's credited to

"80% of dogs over 3 have periodontal disease" is widely repeated in pet product write-ups and articles. The figure is most often credited to a large study conducted at veterinary practices in the United States.

Checking that paper, it states that "dental calculus and gingivitis were the most commonly reported conditions" — but there's no mention of an "80%" figure anywhere in it.

It's a widely repeated figure, but as far as we can tell from the original paper, this study doesn't appear to be its actual source.

② Numbers closer to the measured rate

A large UK clinical-records dataset found that just over 10% of dogs were diagnosed with periodontal disease in a given year. Dogs with periodontal disease also tended to be older than those without.

※This is the rate diagnosed as "periodontal disease" in clinical records — not a figure from a detailed exam under anesthesia.

There's also a report explaining why the numbers vary so widely. It found that a visual check and a detailed exam under anesthesia can produce numbers that differ several-fold or more. In other words, the method of examination alone can shift the reported figure by that much.

In short, what's really going on with your own dog is something you won't know until it's actually checked. If you're concerned about your dog's teeth or gums, having them looked at during a regular checkup can catch things a visual check alone would miss.

③ Plaque takes 1 day, tartar takes 3

You'll often hear "daily to every other day." The reason comes down to how fast things move inside the mouth.

The World Small Animal Veterinary Association (WSAVA) global dental guidelines state that plaque forms on clean teeth within about a day, turns into tartar within about 3 days, and gum inflammation can begin as early as 2 weeks. With once-a-week care, that single gap is long enough for the plaque-to-tartar process to run through twice.

The same guidelines also state that tartar itself isn't the direct cause of periodontal disease. The actual cause is plaque — tartar's role is that its rough surface makes it easier for more plaque to stick.

What needs removing, then, is the plaque that builds up daily. The guidelines also note that removing only the buildup visible above the gumline doesn't stop progression, since periodontal disease advances below the gumline.

④ Brushing frequency — daily to every other day is the benchmark

There's research on brushing frequency too. In a 28-day study on beagles, brushing daily or every other day showed a clear difference in reducing plaque, tartar, and gingivitis compared to brushing once a week or every other week.

There's also research closer to real-world conditions. A study on racing greyhounds found that even once-weekly brushing helped limit tartar buildup, but controlling gum inflammation required daily brushing.

It seems that weekly brushing is worthwhile for tartar control, but if gum health matters too, daily is the benchmark — and even on days that's hard, brushing more often than not still makes a difference.

Some research also points to a link between periodontal disease and overall health. The causal relationship isn't settled, but it seems worth not treating dental health as a completely separate issue from the rest of the body.

⑤ VOHC certification as a reference point

When choosing a dental chew or dental wipe, there's a certification system worth knowing about: VOHC (Veterinary Oral Health Council), a third-party body.

VOHC doesn't test the product itself. It reviews clinical data submitted by the manufacturer through a panel of specialists, and awards a seal to products shown to reduce plaque and tartar by a set amount.

Whether the VOHC seal appears on the packaging is one useful reference point when choosing between the many products on the market.

⑥ A staged approach for reluctant dogs and seniors

Put a toothbrush straight into most dogs' mouths and they'll resist. For seniors just starting dental care, or dogs unused to it, a staged approach is recommended.

  1. Get them comfortable with having their muzzle (the area around the mouth) touched
  2. Get them comfortable with a finger touching their gums
  3. Get them comfortable with a dental wipe, wrapped around a finger, wiping their teeth
  4. Once comfortable, move on to a toothbrush

Spending roughly 1–2 weeks on each stage, without rushing, is the general guideline. It looks like a roundabout way to start, but it tends to be easier to keep up with than starting straight with a toothbrush.

On Rakuten, dental wipes mostly run ¥600–¥1,200 for a pack of around 30, with bulk packs running into the thousands of yen.▶ Hanocare dental wipes, 30 sheets, on Rakuten (693 yen)

⑦ Tartar that's already formed can't be removed at home

Brushing can only prevent things at the plaque stage. Once it's hardened into tartar, it's stuck firmly to the tooth surface, and no tool available for home use can remove it.

The procedure that removes it is called scaling, done at a vet clinic under general anesthesia. In Japan, Japan's Ministry of Agriculture, Forestry and Fisheries (MAFF, Nōrinsuisanshō, 農林水産省) states that tartar removal using a scaler is a medical procedure requiring a veterinarian's clinical judgment and technique. The same page also states that treating animals in someone's care is work only a licensed veterinarian may perform.

The phrase "removing tartar" can sound like routine grooming, on the level of trimming nails. In practice, it's treated very differently.

Brushing hard once tartar has already formed won't remove it. If you notice red gums or unusually strong bad breath, it's faster to have your dog seen before stepping up home care.

⑧ About anesthesia-free tartar removal

You'll sometimes see services offering to remove tartar without anesthesia. For an owner worried about anesthesia risk, that can look like an appealing option.

Veterinary dental specialist bodies, in Japan and internationally, don't recommend it. The reasons they give are specific.

International guidelines state that in an awake animal, the procedure can't reach below the gumline, so the teeth may look clean while inflammation and pain remain underneath. On top of that, they flag a further problem: looking clean can mask the issue and delay the care that's actually needed.

Materials from the Japanese Small Animal Dental Society (Nihon Shōdōbutsu Shika Kenkyūkai, 日本小動物歯科研究会) also raise risks with the instruments themselves: a scaler tip is blade-shaped and tends to slip on the tooth surface, making it easy to injure the gums or tongue of an animal that's moving; there are recorded cases of a tooth breaking along with the tartar when forceps were used to crack it off; and with a loose tooth, there's a risk of the tooth breaking and leaving the root behind, or even fracturing the jawbone.

The same materials also note that after a painful experience, dogs often won't let their mouth be touched at home again. Since daily brushing is the core of periodontal care, losing that is a steep price to pay for how things look in the moment.

※What's described here reflects positions published by specialist bodies and an explanation from a government ministry. It isn't a judgment about any specific shop or service.

⑨ What to ask when you're worried about anesthesia

Still, if a vet says your senior dog needs general anesthesia, saying "sure, go ahead" right away isn't easy for most owners.

A large UK study conducted between 2002 and 2004 found that the rate of death associated with anesthesia or sedation was 0.17% (about 1 in 600) across all dogs. Breaking that down shows a stark difference: 0.05% (about 1 in 1,800) for healthy dogs, versus 1.33% (about 1 in 75) for dogs with pre-existing conditions.

That's more than a 20-fold gap.

The way to read this number is that it depends far more on the animal's health condition at the time than on age itself. It's not specific to dental procedures — it covers anesthesia and sedation overall — and it comes from a study done in another country over 20 years ago. Even so, it's a useful way to reframe the worry from "they're old" to "what's their condition right now."

The same study also reported that roughly half of the deaths happened not during anesthesia itself, but after the dog had come around from it.

When you talk to your vet, these are worth asking:

Materials from the Japanese Small Animal Dental Society also state that anesthesia can't be called 100% safe, while noting that current anesthesia techniques and health assessments keep the risk low. Working from the assumption that the risk isn't zero, and getting the specifics from your vet to weigh it properly, seems like the realistic approach.

⑩ What can happen in the mouth if it's left to progress

Periodontal disease can advance with almost no symptoms visible from the outside, which is part of why it tends to be caught late.

The guidelines list the following as things that can happen in the mouth once it's progressed:

Jaw fractures are reported more often in small dogs, because their teeth are large relative to their body size and the bone around the lower back teeth tends to be thin. These fractures tend to happen from a light bump or during a tooth extraction, and there are reported cases of a jaw breaking simply from eating.

Knowing where "just some bad breath" can lead is a reason to have your dog's mouth checked at a regular checkup too.

⑪ Signs it's time to see a vet

See a vet without waiting if you notice any of the following.

※This page is a general introduction to care ideas. For diagnosis or treatment, please consult a vet.

Frequently asked questions

Is it true that "80% of dogs over 3 have periodontal disease"?

It’s a commonly repeated figure, but when we checked the paper most often cited as its source, we couldn’t find any mention of an "80%" figure. Instead, a large UK clinical-records dataset found that just over 10% of dogs were diagnosed with periodontal disease in a given year.

What's the real rate of periodontal disease in dogs?

Clinical-records-based estimates put it at just over 10%. But there’s also a review noting that the number can differ several-fold or more between a visual check and a detailed exam under anesthesia. Because the number depends so much on how it’s measured, the honest answer is "you won’t know until it’s checked."

How often should I brush my dog’s teeth?

A study on beagles reported a clear difference in plaque, tartar, and gingivitis when brushing daily or every other day, compared to once a week or every other week. A separate study found that even once-weekly brushing helped limit tartar buildup, but daily brushing was the benchmark for controlling gum inflammation.

What if my dog won't let me touch its teeth?

A staged approach is recommended: get them used to having their muzzle touched → then their gums touched → then wiped with a dental wipe → then move on to a toothbrush. Spending roughly 1–2 weeks on each stage, without rushing, is the general guideline.

What is the VOHC seal?

VOHC (Veterinary Oral Health Council) is a third-party body that reviews clinical data submitted by companies through a panel of veterinary dental specialists, and awards a seal to products that meet its standards. It doesn't test the product itself, but it's one useful reference point when choosing between products.

How long does it take for plaque to turn into tartar?

International veterinary dental guidelines state that plaque attaches to the teeth within about a day, turns into tartar within about 3 days, and gum inflammation can begin as early as 2 weeks. That speed is exactly why daily-to-every-other-day brushing is recommended.

Can tartar that's already formed be removed at home?

No. Tartar is stuck hard to the tooth surface, and no tool for home use can remove it. In Japan, the procedure to remove tartar (scaling) is a medical procedure performed by a veterinarian, according to Japan's Ministry of Agriculture, Forestry and Fisheries (MAFF). If you're concerned about your dog's teeth, talk to a vet clinic first.

What about "anesthesia-free tartar removal"?

Veterinary dental specialist bodies, in Japan and elsewhere, don't recommend it. In an awake dog or cat, the procedure can't reach below the gumline (into the periodontal pocket), so the teeth may look clean while inflammation and pain remain. There are also reported cases of teeth or jawbones being broken by the instruments. In Japan, tartar removal using a scaler is also a medical procedure performed by a veterinarian, according to MAFF.

My dog is a senior — I'm worried about general anesthesia.

It’s natural to worry. A large UK study conducted from 2002 to 2004 found that the rate of death linked to anesthesia or sedation was roughly 1 in 1,800 for healthy dogs, versus roughly 1 in 75 for dogs with pre-existing conditions. The way to read that is: health condition matters far more than age itself. Ask your regular vet what tests they can run before anesthesia.

Does having tartar removed cure periodontal disease?

Removing tartar on its own isn't treatment. The actual cause of periodontal disease is plaque, not tartar — tartar's role is creating a rough surface that plaque sticks to more easily. What matters most in the end is whether you can keep up with home care after the procedure.

Read next

Research and sources referenced on this page

We aren't veterinary specialists, so we've kept this to a summary. The originals are listed below.

If you spot an error on this page, please write to [email protected] — we'll check it and fix it.