Bad Breath (Halitosis): Is it normal?

Posted by MyDogDoc on

Bad breath – the medical term is ‘halitosis’ - is an all too familiar problem in dogs.

  • It is so common that it is often accepted as normal.

  • Bad breath in dogs is NOT normal.

  • If your dog has bad breath it is likely to be an indicator for other more serious underlying problems. And some of the most common causes of bad breath, such as dental disease, can easily be treated!

What Causes bad breath in dogs?

There are numerous causes for bad breath in dogs, some of which are preventable if spotted early.

Dental Disease

By far the most common cause is Periodontal Disease. Periodontal disease is inflammation and infection of the gum and supporting structures of the teeth. The build-up of plaque and tartar allows bacteria to thrive, these bacteria produce much of the unpleasant odour or “bad breath”. Decomposing food particles trapped in gum pockets during the periodontal disease process will also give off a bad odour as do rotting teeth and gums. This is what would happen to humans if we never brushed our teeth!


Stomatitis is the term we use to describe inflammation inside the mouth. This can be caused by a variety of things such as infections or eating something which irritates the mouth lining.

Lip Fold Disease

This is especially common in breeds which have loose, folded skin around their lips eg. spaniels, pugs, bulldogs etc. These areas of “skin on skin” create a warm, humid environment ideal for bacteria and yeast to thrive. The folds can also trap food particles causing inflammation, infection and bad smell to develop.

Something Stuck

Pieces of bone or stick can become trapped between the teeth in the mouth. As this starts to rot, bacteria and inflammation set in and so too a bad smell.


Dogs can develop tumours in their mouths, which can become infected with bacteria and start to smell.


Some diets are more prone to producing bad breath than others. Fish based diets can produce a more pungent odour than other types.

Eating Habits

Dogs can have some rather nasty habits. Snacking on other animal faeces, rubbish, dead and rotting animal remains are just a few of these. They can even turn to eating their own faeces too and this is known as coprophagia. All these habits produce lots of bacteria and hence lots of bad breath.

Underlying Disease

Bad breath is not just limited to problems within the mouth. Some diseases can produce a distinctive type of bad breath and if you notice these, it is important to seek vet attention urgently.

  • Liver Disease – dogs with liver disease will often have a foul, sweet musty breath.

  • Kidney disease – breath which smells like urine or ammonia can often be a tell-tale sign of kidney disease.

  • Diabetes – diabetic dogs will often have a sweet, fruity smelling breath (similar to pear drops or nail polish remover).

Gut Problems

Gut upsets, for example, vomiting bugs, blockages and gut infections can lead to bad breath. When a dog’s ‘good gut bacteria’ (normal gut microbiome) is thrown off balance, it can lead to ‘bad bacteria’ flourishing, producing smelly gas and bad breath.

Airway Infections

Any infection in the lungs, throat, nose, sinus or trachea (windpipe) can lead to a smell coming from the mouth.

Anal Gland Infections

When dogs have impacted or irritated anal glands, they will often repeatedly lick around their bottom. This transfers bacteria from their anal gland area to their mouth, causing bad breath.

How is bad breath treated?

The underlying cause of the bad breath will have to be found and you will probably need help from your vet to do this. Once the cause of the problem has been established, the vet will be able to advise on the correct treatment. By treating the cause, the bad breath should improve.

How can I prevent bad breath from occurring in the first place?

Some causes of bad breath cannot be prevented, but prompt identification and treatment will reduce treatment time and suffering for your dog. For some causes such as dental disease, good oral hygiene (including toothbrushing, toothpastes, oral rinses) to help with daily plaque control is key to its prevention. A daily check of your dog’s teeth will have the added advantage of spotting problems at an early stage including changes in breath odour.

Anal sac disease Bad breath Coprophagia Dental disease Diabetes Dog Eating poo Foreign bodies Gum disease Halitosis Health Kidney disease Lip fold dermatitis Liver disease Microbiome Mouth Preventative Care Puppies Stomatitis Teeth Toothbrushing Tumour

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