What is dental disease?
Updated By PetymFacts checked against official sources on
Quick answer
Dental disease in pets is mostly periodontal disease: plaque bacteria inflame the gums (gingivitis) and then destroy the tissue and bone holding the teeth (periodontitis). It is the most common disorder vets diagnose in dogs, and very common in cats. Bad breath, tartar and red gums are the early signs. Daily brushing prevents most of it.
Also called periodontal disease, gum disease, tartar, gingivitis, bad breath in dogs, tooth resorption.
Key facts
- Up to 80% of dogs and 70% of cats have some level of periodontal disease by the age of two. Merck Veterinary Manual
- In UK primary-care records, 12.5% of dogs were diagnosed with periodontal disease in a year; the odds fell as adult body weight rose, and Toy Poodles and King Charles Spaniels were among the breeds at highest risk. Journal of Small Animal Practice (2021)study
- Brushing every day, or at least every other day, appears to be the most effective way to improve and keep gum health. Merck Veterinary Manual
- As many as 85% of cats aged three and over are thought to have some dental disease, and more than 70% of cats over five have at least one painful tooth resorption. International Cat Care
- Periodontal disease has been linked with a higher risk of chronic kidney disease, particularly in cats. Merck Veterinary Manual
What are the signs of dental disease?
Bad breath is not normal dog breath. It is usually the first sign of infection under the gum line.
Look for bad breath, yellow-brown tartar on the teeth, and red, swollen or bleeding gums. Later signs include drooling, pawing at the mouth, chewing on one side, dropping food, loose teeth and a pet that goes off hard food. Many pets with sore mouths keep eating, so a good appetite does not rule it out.
Cats hide mouth pain especially well. International Cat Care describes two common, painful conditions: tooth resorption, in which the tooth erodes, often at the gum line, and feline chronic gingivostomatitis, severe inflammation through the mouth. A cat that eats less, drools or stops grooming should have its mouth checked.
The Merck Veterinary Manual lists toy breeds and misaligned teeth among the risk factors, and in UK records the odds fell as body weight rose. Small dogs popular in Indian flats, such as the Pomeranian, Shih Tzu and Lhasa Apso, deserve extra attention.
What do people get wrong about pets' teeth?
You may have read
Chewing bones keeps teeth clean.
Myth
What the sources say
Teeth may look cleaner, but gum disease was no different in dogs fed raw meat and bones, and hard bones can fracture teeth. WSAVA
You may have read
A scale and polish can be done while the pet is awake.
Myth
What the sources say
Proper cleaning removes plaque and tartar above and below the gum line with instruments, under general anaesthesia, so the vet can also examine every tooth. Merck Veterinary Manual
You may have read
Human toothpaste is fine for a dog.
Myth
What the sources say
Some toothpaste for people contains xylitol, which is dangerous for dogs. Use a toothpaste made for pets. US Food and Drug Administration
You may have read
Dry food alone prevents dental disease.
Myth
What the sources say
Some kibbles with dental claims may help reduce tartar, but daily brushing is still the most effective home care. VCA Animal Hospitals (Canadian Academy of Veterinary Nutrition)
How do you start brushing a pet's teeth?
Go slowly over a couple of weeks, keep sessions short, and reward calm behaviour. Brushing works best on healthy gums; if the mouth is sore, see a vet first.
- Pick a calm time each day and let the pet lick a little pet toothpaste off your finger.
- Lift the lip and rub your finger along the outer surfaces of the back teeth for a few seconds, then reward.
- Move on to a soft pet toothbrush or finger brush, working in small circles where the tooth meets the gum.
- Aim for every day, or at least every other day. Merck Veterinary Manual
- Choose chews and products tested to reduce plaque or tartar; the Veterinary Oral Health Council lists those that meet its standards. Merck Veterinary Manual
- Book a dental check with your vet at least once a year, more often for small breeds and older pets.
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Questions owners ask
Why does my dog's breath smell so bad?
- Usually because of plaque bacteria and gum infection, the early stage of periodontal disease. Up to 80% of dogs have some gum disease by the age of two. Ask your vet to check the mouth. Do not cover it with mints or human products, which can contain xylitol.
Is anaesthesia safe for a dental cleaning?
- A proper clean needs general anaesthesia, so the vet can clean below the gum line, examine every tooth and treat painful teeth without distressing the pet. Your vet will check your pet's health beforehand to reduce the risks. Ask them to explain the plan and the aftercare.
Do cats need their teeth brushed?
- Yes, if they will accept it. International Cat Care says regular toothbrushing is the best way to keep a cat's teeth and mouth healthy. Start slowly with a cat toothpaste on your finger. Cats with tooth resorption or sore gums need treatment from a vet first, often under anaesthetic.
Can I use human toothpaste on my dog?
- No. Some human toothpaste contains xylitol, which can cause dangerously low blood sugar and liver damage in dogs, and pets swallow toothpaste rather than spitting it out. Use a toothpaste made for dogs or cats, and keep family toothpaste and mouthwash out of reach.
Keep reading
Related terms
More in health conditions
- ArthritisArthritis, or osteoarthritis, is a long-term joint disease in which worn cartilage lets the joint surfaces rub, causing stiffness, swelling and pain. It is very common in older dogs and cats. It cannot be cured, but pain relief from a vet, a healthy weight, gentle regular exercise and a few home changes keep most pets comfortable for years.
- Bloat (GDV)Bloat, or gastric dilatation-volvulus (GDV), is when a dog's stomach fills with gas and twists on itself, cutting off its blood supply. It mainly affects large and giant deep-chested breeds. Unproductive retching, a swelling belly, drooling and restlessness are the signs. It is a surgical emergency that can kill within hours.
- BOASBOAS, brachycephalic obstructive airway syndrome, is a breathing disorder of flat-faced dogs. Narrow nostrils, an overlong soft palate and a small windpipe block airflow, so affected dogs snore, snort, tire quickly and overheat easily. It is worse in heat, humidity and obesity. Surgery can widen the airway, and a lean weight helps.
- Canine distemperCanine distemper is a serious viral disease of dogs that can attack the skin, airways, gut and nervous system. It spreads in droplets from coughing, sneezing and barking, and through body fluids. There is no specific cure, and some dogs do not survive even with treatment. The D in the DHPPi vaccine prevents it.
- Canine parvovirusCanine parvovirus, or parvo, is a highly contagious virus that attacks a dog's gut and immune system. It spreads through infected faeces, survives a long time in the environment and hits unvaccinated puppies between 6 weeks and 6 months hardest. Vomiting and bloody diarrhoea can kill within days, and it is prevented by the core vaccine.
- Cat fluCat flu is the everyday name for an upper respiratory infection in cats. More than 90% of cases are caused by feline herpesvirus, feline calicivirus or both. Cats sneeze, have runny eyes and nose and may stop eating. Most recovered cats remain carriers, and stress can bring the virus back. Vaccination usually prevents severe disease.
- Cherry eyeCherry eye is when the tear gland inside a dog's third eyelid slips out of place and shows as a smooth, red, cherry-like lump in the inner corner of the eye. It is common in young Bulldogs, Beagles, Shih Tzus and Pugs, and needs a vet, usually for surgery to put the gland back.
- Chronic kidney diseaseChronic kidney disease (CKD) is a slow, lasting loss of kidney function, common in older cats and also seen in older dogs. Early on there are often no signs; later a pet drinks and urinates more, eats less and loses weight. It cannot be cured, but a kidney diet, water and regular checks can slow it.
- DehydrationDehydration means a pet's body has lost more water than it has taken in, through heat, panting, vomiting, diarrhoea or illness. Early on the gums turn sticky; then the skin loses its spring and the eyes sink. A mildly dehydrated pet needs water and a watchful eye; a weak, vomiting or collapsing one needs a vet now.
- Diabetes in petsDiabetes mellitus is a lifelong condition in which a dog or cat cannot make or use enough insulin, so sugar builds up in the blood. Signs are drinking and peeing more, hunger and weight loss. Most diabetic pets live well on insulin injections given at set times with meals, and some cats go into remission.
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Sources
Each source was opened and read on the date shown. How Petym checks its sources
- Merck Veterinary Manual: Periodontal disease in small animals (full review February 2024, updated April 2025) (opens in a new tab)
- International Cat Care: Dental disease in cats (updated 26 September 2025) (opens in a new tab)
- WSAVA: Frequently asked questions and myths (Global Nutrition Committee) (opens in a new tab)
- US Food and Drug Administration: Paws off xylitol: it's dangerous for dogs (content current as of 17 December 2025) (opens in a new tab)
- VCA Animal Hospitals (Canadian Academy of Veterinary Nutrition): Dry, canned, or semi-moist: food choices for dogs (updated 20 March 2024) (opens in a new tab)
- Journal of Small Animal Practice (2021): Epidemiology of periodontal disease in dogs in the UK primary-care veterinary setting, O'Neill and others (opens in a new tab)