None of us likes to smell bad breath and especially so from our pets. Bad breath in pets can be caused by a digestive problem or be a sign that your pet needs better dental care. Because a buildup of bacteria is usually at the root of halitosis, you should always have your pet’s health checked out if you sense pungent smells coming from their mouths.

Most pet owners associate bad breath with dogs. However, it’s not just dogs that suffer from bad breath as cat’s breath can just as stinky.

What are the causes of your pet’s bad breath and what can this tell you about their general health? When should you take your pet to the vet to have their smelly breath checked out?

Causes of Bad Breath in Pets

Here are the main causes of bad breath in pets.

Dental or gum disease

Just like humans, dogs and cats need to keep their teeth clean to avoid a buildup of plaque and bacteria in the mouth. Usually, you can buy kibble or synthetic bones that pets chew on to help remove tartar and plaque.

It’s also important to have routine dental cleaning carried out by your local vet. This can help prevent gum disease developing which can lead to more health problems. During the dental checkup, your vet will do the following:

  • Remove plaque and tartar
  • Check for other dental issues
  • Remove broken or decayed teeth

Kidney disease

Kidney disease can cause your dog’s or cat’s breath to become smelly. This happens because waste products aren’t eliminated effectively by the kidneys and they build up in the bloodstream. This, in the end, comes out through your pet’s breath.


Your pet’s bad breath could be due to the fact that they are suffering from diabetes. When your pet’s body can’t produce enough insulin, high levels of a blood acid called ketones form. This causes your cat or dog’s breath to have an unusual, fruity sweet smell.

If diabetes in your pet isn’t controlled properly, it can cause a buildup of bacteria in their mouth, which will cause bad breath.

Something stuck in the mouth

If any foreign object is stuck in your pet’s mouth, it will start to decay and rot, causing your pet’s breath to stink. For example, it’s common for cats to get bits of grass stuck in the back of their throat or between their teeth. Splintered bones or pieces of stick can get lodged between teeth and cause foul breath.

There is always that possibility of your pet has been eating some unsavory things like other dead animals or feces. These kinds of “foods” will definitely cause smelly breath.


Unfortunately, dogs and cats can develop cancerous tumors. Oral tumors cause more bacteria to stay in the mouth and cause a foul smell. If you notice that your pet has bad breath and any kind unusual mass or lump in their mouth or throat, you should take them for a checkup as soon as possible.