5 reasons for bad breath in dogs (and how to treat it)

Dog with their mouth open showing bottom teeth
(Image credit: Getty Images)

Bad breath in dogs isn’t the most pleasant of conditions to be dealing with as a pet parent, especially if your canine companion loves nothing more than to smother you with kisses the minute you walk through the door. 

While there are plenty of tips to keep dog teeth clean and healthy (opens in new tab), it’s important to figure out why your beloved bundle of fluff is experiencing bad breath in the first place so that you can then choose the most appropriate form of treatment, which may be as simple as buying the best toothbrush for dogs (opens in new tab).

Although we often just write off a dog’s bad breath as part and parcel of owning a pup, it’s worth noting that while a certain degree of stinky breath is to be expected from time to time, a foul and persistent odor is often the sign of an underlying health issue.

Learning how to brush a dog’s teeth (opens in new tab) can certainly be a useful skill when it comes to preventing plaque and tartar build-up, but other more serious conditions, such as diabetes in dogs, kidney disease, and liver disease, are all potential health issues that can cause bad breath and require specialist intervention. 

Below, you’ll find everything you need to know about bad breath in dogs, including the most common causes, how to treat it and what you can do at home to reduce the risk of it occurring in the future.

What causes bad breath in dogs?

Doggy dental practices have come a long way in recent years with checkups and teeth cleaning becoming a routine part of those annual vet visits. Preventative dental care options are also now widely available and a dog’s mouth is playing a more important role in the early diagnosis of a range of health issues.

While you may be tempted to dismiss the foul odor coming from your canine companion's mouth as just normal stinky dog breath, it’s something that’s worth paying attention to as there’s likely a very good reason behind it. Some of the most common causes of bad breath in dogs include:

1. Oral health issues

Poor oral hygiene practices and periodontal disease are the most common causes of bad breath in dogs. Just like humans, dogs who have crowded, crooked or misaligned teeth are more at risk of plaque and tartar buildup, but even pups with a perfect smile are likely to suffer from dental calculus or gingivitis at some stage in their life.

Too much plaque and tartar can actually result in the gums being pushed away from the teeth, which exposes new areas that bacteria can set up camp in. If left untreated, the gums can become inflamed and infected, and the teeth themselves may even begin to fall out. Needless to say, all of this can lead to some very nasty-smelling breath.

2. Poor dietary habits

Let’s be honest, as much as we love our canine companions, sometimes the things they choose to consume are downright disgusting. From why do dogs eat poop to how to get a dog to stop consuming garbage scraps, many a pet parent has found themselves despairing over the things their beloved bundle of fluff puts in their mouth when they’re not looking. 

Unfortunately, that unsupervised snacking on anything from feces to household objects can lead to rotten smelling breath which can be further exacerbated if your pup is frequently vomiting up all that foreign material that their body isn’t able to digest. 

3. Diabetes

A serious but treatable condition, diabetes in dogs is fairly common, affecting around 1 in 300 pups. Along with symptoms like an increase in thirst and urination, bad breath that has a sweet or fruity smell to it is another key sign of the condition. 

If you notice this or any other symptoms, it’s important to make an appointment with your vet straight away so your dog can get a full examination.

4. Kidney disease

A healthy dog’s kidneys work to regulate hydration, remove toxins, maintain a normal balance of electrolytes and release hormones required to produce red blood cells.

When the kidneys aren’t working properly, either due to an underlying disease or kidney failure, toxins start to build up in the blood and these can cause your dog’s breath to smell like urine. 

If you notice your dog’s bad breath has an ammonia-like quality to it, get your pup checked out by a vet as soon as possible as kidney disease and failure are both serious issues that require immediate treatment. 

5. Liver disease

Alongside the kidneys, the liver acts as a filtration system that removes toxins from the body. If your dog’s breath is truly awful and it’s accompanied by other symptoms such as yellowing of the skin and eyes (jaundice), weight loss, poor appetite and vomiting, liver disease could be to blame. 

Just like with kidney disease, liver disease is a serious condition that can lead to seizures, coma, and even death if left untreated. Make an urgent appointment with your vet or emergency clinic if you suspect your dog may be experiencing liver problems. 

How to treat bad breath in dogs

Vet examining dog teeth

(Image credit: Getty Images)

If your dog has bad breath, the first thing you need to do is to get to the bottom of what’s causing it. You’ll want to schedule a dental exam with your vet who will be able to give your canine companion’s mouth a thorough checking over and assess whether the issue is related to poor oral hygiene or periodontal disease or whether there might be something more serious going on. 

For foul smelling breath that’s been caused by a build-up of plaque and tartar, your vet will be able to book your pup in for a good teeth cleaning and you should notice an improvement in their breath fairly quickly after that. They’ll also be able to remove any loose or damaged teeth and provide advice and guidance on how you can look after your dog’s teeth at home to prevent further problems.

If your vet checks your dog’s mouth and finds their teeth and gums to be in relatively good condition, they’ll likely run further tests to rule out diabetes, kidney or liver disease. Whatever the cause, your dog’s bad breath should go away once the underlying issue has been treated and resolved.

Preventing bad breath in dogs

When it comes to preventing bad breath in your dog, there are several simple things you can do at home to keep those pearly whites in tip-top condition.

1. Regular brushing

Just like we humans need to brush our teeth every day to keep them healthy and looking their best, the same is true for our canine companions. Daily brushing with a specially formulated toothpaste for dogs is the most effective way to prevent plaque and tartar from forming.

Now, a word of warning - your dog probably won’t like getting their teeth brushed at first, but don’t worry, that’s to be expected. You’ll find that over time they’ll get pretty good at tolerating this and it will simply become a part of their daily routine.

To help make it easier, be sure to start off slowly. Spend a few days showing your dog the toothbrush and touching their fur with it without attempting to put it anywhere near their mouth. Let them sniff it and get used to this new object.

Next, pop some toothpaste on the brush and let your dog investigate that. Repeat this for several days, once again without attempting to brush their teeth. After you’ve done this, try popping a bit of toothpaste on their gums so that they can get used to the taste and feel of it.

Once your dog seems comfortable with all of this, you can gently try brushing their teeth for the first time, being sure to reward them with lots of verbal praise and a treat afterwards. 

2. Dental treats

The best dental chews for dogs don’t just help remove plaque and tartar from your pup’s teeth while they chew, they also make for a great treat. Chewing is ideal for keeping the teeth and gums healthy, so be sure to provide your canine companion with plenty of chew toys and dental treats.  

3. Special oral health diet

One final way that you can care for your dog’s teeth at home is to swap them over to a special dental diet. The best dry dog food has a range of kibbles that have been designed with a coarse texture that will sweep away plaque and tartar while your dog chews.

Kathryn is a freelance writer who has spent the past two years dividing her writing time between her two great loves - pets and health and wellness. When she’s not busy crafting the perfect sentence for her features, buying guides and news pieces, she can be found hanging out with one very mischievous Cocker Spaniel, drinking copious amounts of Jasmine tea and attempting to set numerous world records for the longest ever FaceTime calls with her family back home in NZ.