Tartar is plaque that has hardened with minerals from your dog's saliva. Some dogs build it much faster than others, and the reasons fall into two groups. Size, tooth crowding, saliva chemistry and age come with the dog. How often the plaque gets removed, how much the dog chews, the texture of the food and how long it has been since the last vet cleaning are set by the routine.
So if your dog is crusting up faster than the dog next door on the same food, it is probably not something you did wrong. It does mean the parts you control need to work harder. Tartar matters because the plaque living on it keeps the gums inflamed, and that is the road to periodontal disease.
Why two dogs on the same routine end up different
Plaque forms on every dog's teeth every day. What decides how much of it turns to stone is mostly the saliva it sits in. Dog saliva is alkaline, around pH 8 on average in healthy dogs (Iacopetti and colleagues, 2017), and it carries more calcium than human saliva. Lavy and colleagues (2012) suggest this chemistry helps explain why dogs rarely get cavities but build tartar so readily.
Saliva also differs from dog to dog. In that Israeli study, Labradors had higher levels of several salivary minerals than Dachshunds and Jack Russell Terriers, so breed differences exist even if they don't line up neatly with size. A 2022 study of 79 dogs found nearly twice as much phosphorus in the saliva of dogs with plaque, tartar and gum inflammation as in dogs with healthy mouths (Perazzi and colleagues, 2022). That is an early finding and it shows a link, not which came first. If it holds up, it would help explain how two dogs on the same food can end up with very different mouths.
You can't change your dog's saliva. What it sets is how quickly any plaque you miss turns hard. Plaque can set into tartar within days, and our guide to how fast plaque hardens into tartar has the timeline. In a dog with fast-setting saliva, gaps in home care show up as tartar sooner.
Small dogs and crowded mouths
Size is the clearest pattern in the research. In a study of 408 pet dogs examined at a Czech veterinary hospital, tartar was already present in 54% of small dogs (under 10 kg, about 22 lb) aged 1 to 4, compared with 29% of large dogs (over 30 kg, about 66 lb) of the same age. Some small dogs had tartar at one year old (Kyllar and Witter, 2005).
| Age | Under 10 kg | 10 to 30 kg | Over 30 kg |
|---|---|---|---|
| 1 to 4 years | 54% | 49% | 29% |
| 5 to 8 years | 57% | 59% | 43% |
| 9 to 11 years | 77% | 86% | 60% |
| 12 to 13 years | 82% | 89% | 86% |
Share of dogs with tartar at the exam (Kyllar and Witter, 2005). Figures rounded.
Part of the reason is the shape of the mouth. A small dog's teeth are large for its jaw. Measuring X-rays of 234 dogs, Gioso and colleagues (2001) found the first lower molar was proportionally taller against the jawbone in smaller dogs. Teeth packed that tightly, or rotated to fit, leave tight corners where plaque sits undisturbed. A misaligned bite (malocclusion) and baby teeth that never fell out do the same thing. Large UK records point the same way, with the odds of a periodontal disease diagnosis falling steadily as body weight rises (O'Neill and colleagues, 2021).
Age keeps adding to it
In the same Czech study, tartar was found in 49% of dogs aged 1 to 4 and in 84% of dogs aged 12 to 13. Large dogs started later, and by 12 to 13 years they had caught up with everyone else.
Most of that rise is simple accumulation. Every year of partly missed plaque adds another layer, and tartar's rough surface gives fresh plaque a better grip than smooth enamel ever did. An older dog that has never had a dental cleaning is carrying years of buildup, and a new routine on its own won't clear what has already set.
Why the upper back teeth crust first
Lift your dog's upper lip and look toward the back. The big upper cheek tooth, the upper fourth premolar, is usually where tartar is thickest. The duct from the parotid gland, one of the main salivary glands, opens into the cheek right beside that tooth, so it is bathed in fresh saliva all day. It is also the upper carnassial tooth, the big shearing tooth dogs chew with.
The Czech study found the same pattern across the whole group. The upper jaw was more affected than the lower, and tartar was thicker on the cheek side of the teeth than on the tongue side. Left and right sides were affected about equally.
If your dog has heavy tartar on one side and a fairly clean mouth on the other, that isn't the usual pattern. Mention it at the next vet visit, because the reason can be in the mouth rather than in the routine.
The four things you can change
How often plaque comes off is the biggest one. Daily tooth brushing is the most effective home care because it removes plaque before it has time to harden. Brushing twice a week leaves days in which plaque can set. For a small dog or a heavy tartar former, daily is the target. Our guide to clearing plaque before it sets covers the methods.
Chewing comes next. In a survey of 1,350 dogs in North America, the more kinds of chewing material a dog had access to (rawhides, bones, biscuits and chew toys), the less tartar, gum inflammation and bone loss it had (Harvey and colleagues, 1996). Pick chews your dog has to work at but that bend under a thumbnail. Hard items like antlers, hooves and cooked bones break teeth.
Food texture does less on its own. A review of the evidence found soft diets go with more gum disease (Watson, 1994), but in the 1,350-dog survey, dogs fed only dry food showed few differences from dogs on other diets. Switching from wet to dry food on its own is not a tartar plan.
The last factor is the time since the last cleaning. A scale and polish under general anesthetic at the vet is the only way to take tartar back to zero, including below the gumline. After that, home care starts from a clean surface, which is far easier than trying to keep ahead of a crust that is already holding plaque.
Some dogs build plaque despite a good routine. One Caniclean customer, Ann-Sophie Wante, described her dog in a review on November 21, 2023. "Despite giving dried meat on a daily basis to clean his teeth, Storm kept having plaque and a stinky breath." Chewing alone wasn't enough for Storm. That is why brushing stays at the top of the list, with chews as a help rather than a replacement.
When heavy tartar needs a vet
Tartar keeps live plaque pressed against the gum, and that is how most dogs move toward gum disease. Still, the crust you can see is not a reliable gauge of what is going on underneath. The Czech researchers found that the amount of tartar did not always match how inflamed the gums were (Kyllar and Witter, 2005). Some dogs with thick crusts had fairly mild gum inflammation, and the damage that matters most sits below the gumline, where only a vet examination under anesthetic can measure it.
Book a vet visit rather than changing the routine if you see red or bleeding gums, a loose or broken tooth, a swelling on the face or under one eye, or if your dog drops food, chews on one side or stops eating. Don't try to chip tartar off at home. Scraping can damage the enamel and gums and does nothing for the part below the gumline.
If your dog has a thyroid or kidney condition, is pregnant or is a young puppy, check with your vet before adding any new chew or supplement to the routine.
Common questions
Why is tartar building up so fast on my dog's teeth? Usually a mix of a dog that forms tartar easily (small, older, crowded teeth, mineral-rich saliva) and gaps of more than a day or two between plaque removals. Plaque can harden within days, so a weekly routine falls behind.
Do small dogs get more tartar? Yes. In a study of 408 dogs, 54% of dogs under 10 kg aged 1 to 4 had tartar, against 29% of dogs over 30 kg of the same age (Kyllar and Witter, 2005). Their teeth are large for their jaws, which leaves tight spaces for plaque.
Does dry food stop tartar? Not on its own. In a 1,350-dog survey, dogs fed only dry food showed few differences from other dogs, while access to chewing material made a clearer difference (Harvey and colleagues, 1996).
Will tartar come off on its own? No. Once plaque has mineralized, brushing and diet won't remove it, and chewing scrapes off only some of the visible crust. Only a scale and polish at the vet takes it all off, including below the gumline. Home care afterward slows new tartar from forming.
References
- Gioso MA, Shofer F, Barros PS, Harvey CE. Mandible and mandibular first molar tooth measurements in dogs: relationship of radiographic height to body weight. Journal of Veterinary Dentistry 2001;18(2):65-68. PMID 11968914.
- Harvey CE, Shofer FS, Laster L. Correlation of diet, other chewing activities and periodontal disease in North American client-owned dogs. Journal of Veterinary Dentistry 1996;13(3):101-105. PMID 9520786.
- Iacopetti I, Perazzi A, Badon T, Bedin S, Contiero B, Ricci R. Salivary pH, calcium, phosphorus and selected enzymes in healthy dogs: a pilot study. BMC Veterinary Research 2017;13:330. PMID 29126424.
- American Veterinary Dental College. Companion animal dental scaling without anesthesia (position statement, adopted 2004). https://avdc.org/wp-content/uploads/2019/AVDC-pos-stmts/Dental_Scaling_Without_Anesthesia.pdf
- Kyllar M, Witter K. Prevalence of dental disorders in pet dogs. Veterinarni Medicina 2005;50(11):496-505. doi:10.17221/5654-VETMED.
- Lavy E, Goldberger D, Friedman M, Steinberg D. pH values and mineral content of saliva in different breeds of dogs. Israel Journal of Veterinary Medicine 2012;67(4):244-248.
- Lowe C, Anthony J. Pilot study of the effectiveness of a xylitol-based drinking water additive to reduce plaque and calculus accumulation in dogs. Canadian Veterinary Journal 2020;61(1):63-68. PMID 31892757.
- Niemiec B, Gawor J, Nemec A, et al. World Small Animal Veterinary Association Global Dental Guidelines. Journal of Small Animal Practice 2020;61(7):E36-E161. PMID 32715504.
- O'Neill DG, Mitchell CE, Humphrey J, Church DB, Brodbelt DC, Pegram C. Epidemiology of periodontal disease in dogs in the UK primary-care veterinary setting. Journal of Small Animal Practice 2021;62(12):1051-1061. doi:10.1111/jsap.13405.
- Perazzi A, Ricci R, Contiero B, Iacopetti I. Evaluation of salivary biochemistry in dogs with and without plaque, calculus, and gingivitis: preliminary results. Animals 2022;12(9):1091. PMID 35565518.
- Watson AD. Diet and periodontal disease in dogs and cats. Australian Veterinary Journal 1994;71(10):313-318. PMID 7848177.