No problem turns up in Shih Tzus' vet records more often than periodontal disease. In UK records for 2,423 Shih Tzus, 9.5% were diagnosed with periodontal disease in a single year, and among those over 7 it was 18.3% (Dale and colleagues, 2024). The breed's short face adds problems of its own, an underbite that the breed standard asks for and teeth that crowd and turn in a short jaw.
Shih Tzus share the problem our page on why small dogs have worse teeth explains, 42 adult teeth in a jaw built for far fewer. How gum disease starts and why it can't be undone once it reaches the bone is in our guide to periodontal disease in dogs.
What vet records show for Shih Tzus
Those figures come from the VetCompass project at the Royal Veterinary College, whose researchers went through the 2016 records of 2,423 Shih Tzus for every condition, not just teeth.
Age is the big divide. Only 1.5% of Shih Tzus under 2 had gum disease recorded, against 9.1% at 2 to 7 years and 18.3% over 7. A Shih Tzu often lives into its teens (the median age at death in the same records was 12.7 years), so most owners face the older years.
As a small, flat-faced breed, the Shih Tzu is prone to dental disease, because a full set of teeth has to fit a short jaw. The breed's own UK records show a lower rate than that reputation suggests. The 9.5% sat below the 12.5% for all dogs, and in a larger UK study of 22,333 dogs the Shih Tzu's odds of a diagnosis were no different from crossbreds' (O'Neill and colleagues, 2021). The breed study's authors still named oral hygiene a priority for Shih Tzus. Records also miss disease that only an exam under anesthesia finds, so we read them as showing that gum disease is common in Shih Tzus and rises with age, not that the breed is spared.
The underbite is the breed standard
A Shih Tzu is meant to have an underbite. The American Shih Tzu Club standard, which the AKC uses, asks for an undershot bite and lists an overshot bite as a fault. The UK Royal Kennel Club asks for a mouth that is "slightly undershot or level". Vets call it a class 3 malocclusion, where the lower jaw sits ahead of its normal place against the upper jaw. In most dogs the upper front teeth close just in front of the lower ones.
An underbite that is normal for the breed can still cause trouble. In a flat-faced dog the upper front teeth can press on the floor of the mouth or on the lower canines, which can be painful. When a tooth is damaging gum or another tooth, veterinary dentists usually recommend treatment. That can mean taking the tooth out, shortening it, or moving it.
In the UK records, vets recorded an underbite as a diagnosis in 1.4% of Shih Tzus. The American standard also gives owners a simple check, because it says a Shih Tzu's teeth and tongue should stay hidden when its mouth is closed. Ask your vet to look at the bite if your Shih Tzu's teeth show with its mouth shut, if you find a sore spot or a dent in the gum where a tooth lands, or if it chews carefully on one side.
Crowded and turned teeth in a short face
The standard asks for a muzzle about an inch long, and behind it sit the same 42 adult teeth a Labrador has. In a Shih Tzu, the small premolars along the side of the jaw often sit at odd angles instead of in a neat row, and plaque packs into the gaps between them. Those gaps, not the flat outer faces of the teeth, are where brushing a Shih Tzu needs the most care.
Flat-faced breeds as a group carry a little more gum disease than dogs with longer faces, even though the Shih Tzu's own UK records don't show it.
Baby teeth and missing teeth
In the UK records, 8.5% of Shih Tzus under 2 had a baby tooth that stayed put, falling to 1.3% at 2 to 7 years and none over 7. In a jaw this short, a baby tooth left beside its adult tooth can push the adult one further out of line, so AAHA wants them dealt with as the adult teeth come in. If you see two teeth in one spot, leave the baby tooth for the vet rather than pulling it yourself. Our puppy teething timeline shows when each one should be gone.
Count teeth as well as looking for doubles. In X-rays from a dental referral practice, Shih Tzus were among the breeds most likely to have a cyst around an adult tooth that had never come through, along with Pugs, Boxers and Boston Terriers (Babbitt and colleagues, 2016). So a gap in a Shih Tzu's row of teeth is worth an X-ray. What the vet can do about a buried tooth is covered in our guide to when teeth need pulling.
Brushing a flat face
Brushing a Shih Tzu means working around hair, a short jaw and a crooked row of teeth. It is still worth doing every day or every other day, which kept plaque and tartar lower than weekly brushing in a Beagle trial (Harvey and colleagues, 2015). This is what we suggest for the short face.
- Tie the topknot up first. The Royal Kennel Club standard recommends it anyway, and you can't brush what you can't see.
- Sit the dog sideways on your lap. With barely any muzzle to hold, support the chin from below with one hand and use that thumb to raise the lip at the corner.
- Use a finger brush or a very small soft brush, with dog toothpaste only. Our guide to brushing a dog's teeth covers the angle and the strokes.
- Work the tip of the brush into the gaps between turned premolars with short strokes, rather than sweeping along a row that isn't straight.
- Because the lower front teeth sit in front, lift the upper lip on its own to reach the front of the upper incisors, which are easy to miss.
- A Shih Tzu breathes through a narrow airway, so keep your fingers away from its nose, stop if it snorts or struggles for breath, and keep each session short.
If your Shih Tzu pulls away every time, its mouth may be sore, perhaps where a tooth lands on the gum, so have the vet look before you push on. If it won't accept a brush at all, Caniclean gets round the problem of the hair and the short jaw, because it's a seaweed powder you add to meals, made to help reduce plaque and new tartar. The pack gives the amount by weight. A powder can't move hardened tartar, and it does nothing for a tooth that is hitting the gum. Before starting it, or any chew or supplement, talk to your vet if your Shih Tzu has thyroid or kidney trouble, is pregnant, or is a young puppy.
Cleanings under anesthesia
A tooth that never came through, and any cyst around it, only shows on dental X-rays. Those X-rays need general anesthesia, and so does cleaning below the gumline, so both happen at the same full cleaning. A scrape on an awake dog, as some groomers offer, can reach neither, and the American Veterinary Dental College advises against it. Our page on awake, anesthesia-free cleaning explains why. The first full cleaning should be done by 1 year old, as AAHA recommends for small breeds.
Flat-faced dogs need more care around the anesthetic. In a study of 223 flat-faced dogs matched with 223 others, problems after anesthesia came up in 13.9% against 3.6%, and the authors recommend careful monitoring (Gruenheid and colleagues, 2018). Ask your clinic who watches your dog until it is fully awake and the breathing tube is out. Our guide to anesthetic risk at a dental cleaning gives the figures for dogs in general.
When to see the vet
Book a check for any of the bite problems above, or if a puppy over 6 months has two teeth in one spot or a gap where a tooth should be. Other signs of gum disease, such as red gums or an adult tooth that moves, are worth a visit too. If your Shih Tzu stops eating, has a swollen face or cries when it chews, go the same day.
Leave your own painkillers in the cupboard. The FDA warns that acetaminophen can damage a dog's liver and that human anti-inflammatories aren't necessarily safe for dogs, so call your vet instead.
Common questions
Do Shih Tzus have bad teeth? Their crowded, turned teeth make dental problems likely, and gum disease is the most common diagnosis in their UK records. UK vet records don't show a higher rate than in dogs overall, but it roughly doubles after age 7, so daily cleaning matters.
Is an underbite normal in a Shih Tzu? Yes. The US breed standard asks for an undershot bite and the UK standard for a slightly undershot or level one. It needs a vet when teeth show with the mouth shut or a tooth is rubbing gum or another tooth.
At what age do Shih Tzus lose their teeth? Baby teeth fall out between about 3 and 7 months. A grown Shih Tzu losing a tooth is a different matter, usually gum disease in the bone around it, and worth a vet check.
Can a Shih Tzu live without teeth? Yes. A toothless Shih Tzu can eat once its gums have healed, starting on soaked or soft food.
References
- American Shih Tzu Club. Official standard of the Shih Tzu (American Kennel Club). Approved 1989.
- American Veterinary Dental College. Nomenclature (occlusion and malocclusion). Companion animal dental scaling without anesthesia, position statement.
- Babbitt SG, Krakowski Volker M, Luskin IR. Incidence of radiographic cystic lesions associated with unerupted teeth in dogs. Journal of Veterinary Dentistry 2016;33(4):226-233. doi:10.1177/0898756416683490.
- Bellows J, Berg ML, Dennis S, et al. 2019 AAHA Dental Care Guidelines for Dogs and Cats. Journal of the American Animal Hospital Association 2019;55(2):49-69. doi:10.5326/JAAHA-MS-6933.
- Dale F, Brodbelt DC, West G, Church DB, Lee YH, O'Neill DG. Demography, common disorders and mortality of Shih Tzu dogs under primary veterinary care in the UK. Canine Medicine and Genetics 2024;11:2. doi:10.1186/s40575-023-00135-y.
- Gruenheid M, Aarnes TK, McLoughlin MA, et al. Risk of anesthesia-related complications in brachycephalic dogs. Journal of the American Veterinary Medical Association 2018;253(3):301-306. doi:10.2460/javma.253.3.301.
- Harvey C, Serfilippi L, Barnvos D. Effect of frequency of brushing teeth on plaque and calculus accumulation, and gingivitis in dogs. Journal of Veterinary Dentistry 2015;32(1):16-21. doi:10.1177/089875641503200102.
- 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.
- The Royal Kennel Club. Shih Tzu breed standard. Last updated April 2025.
- US Food and Drug Administration, Center for Veterinary Medicine. Get the facts about pain relievers for pets. 2022.