It’s surprising what you can learn from teeth. Evolutionary scientists love studying fossilised animal teeth to pinpoint major climate changes across time. That gives them crucial insight into how animals may adapt to the inevitable environmental changes happening on our planet.

At a more local level, vets also love studying their patients’ teeth, but for very different reasons. Dental disease can cause all sorts of problems for animals, making them miserable and even shortening their lives if ignored. Statistics from the Australian Veterinary Association suggest that by three years of age u,p to 80% of dogs and cats show some signs of dental disease.

Apart from really bad breath and horrible toothache, untreated dental disease can result in abscesses, bone infections and eventually holes in the nasal cavity. If bacteria enter the bloodstream, organs such as the heart, liver or kidneys can be damaged. No wonder animal rescue groups routinely check teeth before clearing a dog or cat for adoption. Inevitably, this adds to the veterinary expenses that rescues must absorb to ensure the well-being of all animals in their care.

There’s no doubt that dental treatment can be expensive depending on what needs doing – or the grade of dental disease with which your beloved friend has been assessed. This can range from Grade 0, with beautiful pearly whites and sweet-smelling breath, to Grade 4 that can mean potential tooth loss, pus-like discharge, pain and smelly breath that leaves you gasping for air. In-between there is mild inflammation of the gums and tartar build-up (Grade 1), more advanced gum disease with plaque and tartar extending under the gum line and affecting the bone (Grade 2) and advanced gum disease, significant plaque and tartar, some tooth mobility and bone loss (Grade 3).

While the mild inflammation, called gingivitis, is reversible, the next stage, periodontitis, is not. It’s an irreversible, destructive process involving loss of the tooth’s supporting structures, with eventual surgery an almost inevitable outcome.

Sometimes it’s the breath that prompts a visit to the vet, but by then your beloved dog or cat has probably been suffering in silence and stoically putting up with toothache for a long time. Not showing pain is a survival technique inherited from their wild ancestors, who knew that revealing any sign of weakness could turn them from top predator to potential prey.

The signs of toothache can be subtle. There may be more drooling than usual, or a reluctance to eat dry food, including their favourite hard treats. Food may drop out of their mouth while chewing, or they may try to swallow dry food whole. Sometimes they will paw at their mouth, but become distressed, or even aggressive, if you try to go near their face or mouth to check. They may shake their head as if trying to dislodge the relentless pain they are feeling. And their weight may start to drop, which should raise alarm bells but can be easily missed in a very hairy dog or cat. But don’t be fooled – toothache is a silent pain that can escalate over time, and while your pet can’t articulate what they’re feeling, the signs are definitely there.

What can you do?

Regular dental checks are important, and you’ll find that every August, during National Pet Dental Health Month in Australia, many vets will offer free check-ups and discounts on any subsequent dental work. Most procedures – even a scale and polish – will require a general anaesthetic. Checking, cleaning and polishing 42 teeth in a dog or 30 teeth in a cat, especially if there is any tenderness, is impossible in a wide-awake, stressed patient. Even an X-ray is difficult when needing to position and keep a sensor in the patient’s mouth while they lie perfectly still. Of course, some pets may need extra care and attention when anesthetised due to some general health conditions, and that’s something you’ll need to discuss with your vet.

Maintaining your pet’s teeth

Now that your dog or cat’s teeth are beautifully clean and it’s a pleasure to have them breathe in your general vicinity again, what can you do to keep them that way? Toothbrushing is one option, but you need to start slowly and gently train them (even your cat!). It needs to be a fun time culminating with a reward when it’s over. Use a soft brush and pet toothpaste, or just water – not your minty fresh toothpaste that your dog or cat will probably swallow given they haven’t mastered the rinse and spit routine. Unfortunately, while brushing is good in theory, some dogs and cats will clamp their jaws shut with more power than a crocodile and nothing will get them to open up. This can be especially difficult with some of the flat-faced dogs and cats who are even more prone to dental disease with their crowded mouths and misaligned teeth inside their shortened muzzles.

Chewing appropriate dental products, an oral care diet and using oral additives in their water can help, as reported in a 2025 article “Bridging the Gap in Dental Care” in Veterinary Practice magazine. After testing various combinations of brushing, dental chews and water additives for 16 weeks among 125 dogs, researchers found some effective combinations included weekly brushing and a daily water additive, or a daily high-quality dental chew and daily water additive. However, it’s important to talk to your vet about options that could work best for you and your dog or cat.

Some tips for brushing teeth

Find a calm and relaxed time and start slowly. But remember, if your pet already has existing dental disease, even a slow start won’t help because they’re more likely to be defensive of their sore mouth. If you’re unsure about the health of their teeth, get a dental check before starting. Don’t hold them down or continue if they’re showing signs of stress or discomfort. One suggestion is to start with a piece of gauze wrapped around your finger to get them used to the rubbing motion before upgrading to a soft finger brush or soft toothbrush. Tilt their chin upwards to encourage them to relax their mouth, then gently part their lips with one hand and brush with the other hand.

If you’re using a pet-friendly toothpaste, let your pet sample it to get used to the taste. Then brush in a circular motion along the gum line, with the brush ideally at around a 45-degree angle against each tooth for a few seconds. Take as many breaks as you and your pet need to get the job done and keep talking gently throughout the process. At the end, big cuddles all round and a treat.

Final thoughts…

Remember, bad breath is not normal in your best friend. There are exceptions, of course, when your dog snacks on poo or rubbish delicacies while out walking, but in general, their breath should not be offensive. And even though the signs of dental disease may be subtle, that doesn’t mean your dog or cat isn’t in pain. This becomes abundantly clear when suddenly they’re acting years younger with the instant relief that can come with a necessary dental procedure.

More information:

Gawor J, Jank M, Harvey CE, Nicolas CS. Effectiveness of Dental Homecare Protocols in Unscaled Dogs. Journal of Veterinary Dentistry. 2024;42(3):176-181. doi:10.1177/08987564241292769