Last Updated: 18/08/2026
How to Treat Dog Bad Breath
Is your dog’s breath less than fresh? Discover the common causes of bad breath in dogs and practical, vet-recommended ways to get those kisses back.
Author: Dr Teagan Lever BVSc (Hons)
Reading Time: 4 minutes - short read
Don't let foul breath stop you from getting up close and personal with your pooch. If your doggo's kisses are starting to smell less than appealing, it's important to look further to find out what's really going on, because bad breath is often your dog trying to tell you something.
What causes bad breath in dogs?
Bad breath in dogs almost always comes down to one of four things: dental disease, diet, gut issues, or an underlying medical condition.
Dental disease is by far the most common culprit. Inflammation of the gums and bacteria growing in the mouth create smelly sulfur compounds, which is what gives plaque related breath that classic fishy or rotten smell. At least 80% of dogs over the age of 3 have some degree of dental disease, so a dental check with your vet is always the first step.
Diet can play a part too. Fish oil supplements are a common cause (worth it for the omega-3 benefits, in our opinion), and raw or home prepared diets can throw off the normal balance of bacteria in your dog's mouth and gut. Food left sitting in the teeth can also feed the bacteria that cause bad breath.
Gut issues can be behind it too. Ongoing vomiting, reflux or digestive upsets can carry through to breath that smells off, even when the mouth itself looks healthy.
Then there are medical causes that go beyond the mouth: diabetes can give breath a sweet or acetone smell, kidney disease can make it smell like ammonia or urine, and liver disease or oral tumours can cause a foul, sometimes rotten smell as toxins or dead tissue build up.
In clinic, fishy breath is one of the things we get asked about most, and it's almost always dental disease rather than anything sinister. True kidney or liver related breath changes are rarer, but they smell distinctly different.
Is it dental, or something more serious?
The smell itself is often the biggest clue. Fishy or rotten breath is almost always dental, while a sweet or ammonia-like smell can point to something happening internally.
Dental related bad breath usually comes with other signs like visible tartar, red or bleeding gums, pawing at the mouth, or reluctance to chew on one side. If the smell is different, sweet or like nail polish remover can point to diabetes, while an ammonia or urine-like smell can be a sign the kidneys aren't filtering toxins properly.
This is the one distinction we ask owners to watch for: dental bad breath tends to build up gradually over weeks or months, while a sudden, sharp change in the smell of your dog's breath, especially if it smells sweet or like ammonia, is more likely to be medical and worth vet attention ASAP rather than a wait-and-see dental clean.
When should I be worried about my dog's breath?
Bad breath on its own is rarely an emergency, but if it comes with any of these signs, it's time to book a vet visit ASAP.
- Sudden or rapidly worsening bad breath
- Increased thirst or urination
- Unexplained weight loss or reduced appetite
- Vomiting, diarrhoea or lethargy
- Drooling, bleeding gums or a visible lump in the mouth
- Breath that smells sweet, like acetone, or like ammonia
Any of these alongside bad breath means it's worth getting bloodwork and a full check, not just a scale and polish.
What home remedies actually work for dog bad breath?
For dental disease, daily brushing is the single most effective thing you can do, and dental diets, VOHC-approved treats and water additives can help on top of that, but none of them work as a stand-alone fix.
Brushing your dog's teeth daily removes the plaque and food particles that cause smelly breath before they get a chance to build up.
Read our full guide on How to Brush a Dog's Teeth for a step-by-step approach and watch Dr Olivia's video.
Dental diets and VOHC-approved dental treats and chews can genuinely help reduce plaque and tartar, provided your dog chews properly rather than gulping them down.
See our picks for the Best Dental Chews for Dogs and Best Dog Toothpaste.
Water additives and dental powders can freshen breath a little, but they're a top-up, not a substitute for brushing.
What doesn't work: coconut oil, parsley, and breath sprays. We hear about these a lot, and while they might mask a smell for an hour, they do nothing for the bacteria or plaque causing it. The other common mistake we see is owners relying on water additives or supplements alone and skipping brushing altogether, when the two are meant to work together.
Top products to freshen your dog's breath
For the full day-to-day dental care routine, including brushing technique, dental diets and prescription options, head to the Dental Care for Dogs hub.
By checking in with your vet and taking some steps to support your dog's dental health, you can get their breath back to smelling fresh and clean, ready for lots of slobbery doggy kisses!
Dog Bad Breath FAQs
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History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Tue 18 Aug 2026
Edited by Dr Gillian Hill BVSc (Hons)Dr Teagan Lever BVSc (Hons)
Head Veterinarian, BVSc (Hons)
Pet Circle's Head Veterinarian, Dr Teagan graduated from the University of Queensland in 2010 and went on to work in small animal and mixed practice in various locations around QLD & ACT before joining Pet Circle in early 2016. Dr Teagan has special interests in dermatology, nutrition and preventative health care. She feels privileged to witness the special bond people share with their pets on a daily basis and enjoys forming lasting relationships with pet parents and their fur children.
