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Home > Dogs > Is A Dog’s Bad Breath Typically From Their Stomach? Vet-Reviewed Facts

Is A Dog’s Bad Breath Typically From Their Stomach? Vet-Reviewed Facts

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Dr. Nia Perkins

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If you’ve noticed that your adorable dog has breath that smells like rotting garbage, you might be curious about the cause of the stench. Does your dog’s bad breath typically come from their stomach, or is there another source? Stomach issues can cause bad breath in dogs, but there are several other culprits as well, including some serious medical conditions.

In this article, you’ll learn how your dog’s stomach health impacts their breath. In addition, we’ll discuss some of the other causes of bad breath and what steps you can take to improve your pup’s stinky kisses.


How Tummy Trouble Leads To Bad Breath

Normally, a healthy canine digestive tract contains a balance of bacteria, which aids in the digestion and absorption of food. Any disruption in this balance or an overgrowth of unfamiliar bacteria can cause smelly breath in your dog. This bacteria absorbs into the bloodstream from the stomach, then travels to the mouth where the dog breathes it out.

Any type of digestive issue can alter your dog’s gut bacteria and cause bad breath. However, it is especially common for dogs who eat raw food or a home-cooked diet. Raw diets may contain dangerous bacteria, such as Salmonella, that can build up in your dog’s stomach.

It can be difficult to make sure that homemade diets are nutritionally balanced. A lack of essential nutrients can lead to bacterial imbalances and eventually result in bad breath.

sick australian shepherd dog
Image Credit: Irini Adler, Pixabay

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Other Causes of Bad Breath

Besides rogue stomach bacteria, there are several other causes of doggie bad breath.

1. Dental Problems

Dirty teeth and diseased gums, or periodontal disease, are one of the most common causes of bad breath in dogs. Like humans, dogs can build up tartar and plaque on their teeth, especially if they don’t receive regular dental care as part of their grooming routine. Their gums can also become inflamed.

Mouth tumors, more common in older dogs, can also cause bad breath if they become infected or begin to rot away.

2. Something They Ate

Many dogs seem to have an unfortunate taste for eating things humans find disgusting, such as dead animals or cat poop that can make their breath stinky. Sometimes, they eat foreign objects like sticks, that may become lodged in their mouths, eventually becoming infected and smelly. Certain toxic substances can also cause your dog’s breath to smell rotten if ingested.

vet checking dog teeth
Image Credit: Yavdat, Shutterstock

3. Other Medical Conditions

Certain medical conditions, some of them life-threatening, can also cause bad breath.

For example, dogs with kidney disease can develop breath that smells like ammonia because a chemical called urea builds up in their bloodstream. Dogs whose diabetes is not well-controlled or dogs with liver disease may also develop bad breath as a side effect of these conditions.

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What To Do If Your Dog Has Bad Breath

If you’re feeding your dog a homemade diet, double check the recipe with your veterinarian to ensure it is complete and balanced and avoid any nutritional deficiencies that could lead to bad breath. Most veterinarians recommend avoiding raw diets anyway because of the dangers to humans and animals. This precaution can also help your dog’s breath.

Include dental care, such as brushing or oral health products, into your dog’s grooming routine. Some breeds that are more prone to dental disease may need regular cleanings from your veterinarian.

If your dog’s teeth seem clean, but you still smell bad breath, have your dog examined by a vet to check for foreign objects or tumors.

If a medical condition is causing your dog’s bad breath, you will likely notice other symptoms as well, such as:

  • Weight loss
  • Vomiting
  • Excessive drinking and peeing
  • Yellowish eyes and gums
  • Lethargy
  • Loss of appetite

As we discussed, many of the medical conditions that cause bad breath can be serious or even life-threatening. See your veterinarian as soon as possible if you observe any of these symptoms.



Loving your dog doesn’t always mean loving everything about them–such as their bad breath. While your dog’s stomach could be responsible for their breath, it’s not the only possible cause. Don’t assume bad breath is just a normal dog trait you have to live with. It could be a sign of a serious problem. Even if it isn’t, there are steps you can take to help improve your dog’s stinky mouth.

Featured Image Credit: RogerMayhem, Pixabay

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