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

Last updated: August 9, 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

"80% of dogs over 3 have periodontal disease" — a line you'll often see in pet product write-ups and articles. This page checks where that number actually comes from, then covers the real figures and how to keep up with brushing. 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.

The number itself simply isn't there.

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. We cover a closer-to-real, measured figure in section ②.

② What does the measured rate actually look like?

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 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.

④ 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.

⑤ 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.▶ Browse dog dental wipes on Rakuten

⑥ 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.

Read next

Research and sources referenced on this page

We aren't veterinary specialists, so we've kept this to a summary. Sources are listed below for anyone who wants to check the originals.

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