Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Why Does My Dog’s Breath Stink? 8 Vet-Reviewed Reasons

dog breathing

Dogs generally don’t have pleasant-smelling breaths, but it should not be noticeably foul. It’s normal to smell your dog’s breath when they are close to your face or licking you. However, if they are panting and stinking up the room with their foul breath, then something isn’t right. A healthy dog’s mouth should have a mild smell similar to their food.

If your dog’s breath has a strong fishy, rotten meat, musty, or other overpowering smell, here are eight possible reasons why.

divider dog paws 4 oct 2024

The 8 Reasons Why Your Dog’s Breath Stinks

1. Periodontal Disease

Periodontal and gum disease are common oral diseases that affect about 80% of dogs over 3 years old. Periodontal disease refers to an infection around the periodontal ligament that surrounds the root of the tooth, anchoring it in its socket. They are caused by a build-up of tartar that forms on a dog’s teeth when calcium salts in the saliva are deposited onto plaque bacteria. There are many signs of periodontal disease in dogs and bad breath is a major sign. Their breath may have an overpowering rotten smell that worsens depending on the severity of their oral health.

Signs your dog may have periodontal disease include:
  • Inflamed gums
  • Loose or missing teeth
  • Bleeding gums
  • Thick layer of tartar on the teeth
  • Exposed tooth roots
  • Halitosis (bad breath)
  • Appetite changes
  • Difficulty chewing
  • Pawing at the mouth
dog with brown teeth
Image Credit: PixieMe, Shutterstock

2. Gingivitis

Gingivitis refers to gum inflammation and is an early stage of periodontal disease. It is the only reversible stage of periodontal disease and can be treated with professional teeth cleanings and by regularly maintaining a dog’s oral health. Bad breath and inflamed, bleeding gums are signs a dog could have gingivitis.

If left untreated, gingivitis can develop into an advanced stage of periodontal disease that can cause tooth loss.


3. Digestive Issues

Your dog’s digestive health can affect how good or bad their breath smells. If your dog’s oral health is good, their bad breath could be caused by something internal, like digestive issues. These digestive issues can range from gastroenteritis, acid reflux, food intolerances, gastrointestinal cancer, and intestinal blockages.

Many digestive issues cause dogs to vomit, which can cause their breath to have a potent sour smell. This sour smell is caused by the bile and can even be smelt from dogs with acid reflux issues, even if they haven’t been vomiting.

Dog vomit in the living room on the floor
Image Credit: cunaplus, Shutterstock

4. Dietary Habits

Your dog’s diet can have a heavy influence on how their breath smells. Although it is normal for dogs to have a mild-smelling breath that reflects the last thing they ate, certain things they try to eat or lick can cause foul breath.

Dogs that are eating diets containing seafood or fish oil supplements could have fishy breath shortly after eating.

Dogs that eat poop, whether it is their own or straight from a cat’s litterbox, could have a foul-smelling breath too. This is known as coprophagia and although we may find it gross, it is common for dogs to do. However, it does not have a good effect on your dog’s breath, and you probably won’t look forward to their kisses afterward.


5. Oral Cavity Disease

Aside from the teeth, the oral cavity includes the bones of the jaws, the tongue, the soft palate, the gums, and the inner lining of the cheeks. Injuries inside the mouth are fairly common and can lead to infection and necrosis of soft tissues, which give your dog bad breath. Unfortunately tumors can arise from any of these tissues which also lead to necrosis and bad breath.

vet checking dog teeth
Image Credit: YAKOBCHUK VIACHESLAV, Shutterstock

6. Canine Diabetes

Diabetic dogs can have bad breath because of ketoacidosis. Ketoacidosis is a life-threatening complication of diabetes in dogs and occurs when the body doesn’t produce enough insulin, and the body is forced to burn fat. Fat burning produces ketones which are toxic when they accumulate in the blood. Diabetic dogs in ketoacidosis have a sweet, fruity-smelling breath or a breath that smells like acetone. Interestingly, only certain people have the ability to smell ketones, possibly due to genetics.


7. Kidney Disease

Dogs with kidney disease or failure could have an ammonia-smelling breath caused by excess urea in the body. The kidneys are responsible for filtering waste products from the bloodstream and converting them to urine to be removed from the body.

In dogs with impaired kidney function, these waste products (urea) build up and cannot be effectively removed from the body through urine. Instead, the excess urea gets converted to ammonia when it reacts with saliva and is exhaled with each breath. This is what gives dogs with kidney disease a breath with an ammonia odor.

Female vet examining sick and sad Rhodesian ridgeback dog
Image Credit; Zontica, Shutterstock

8. Anal Glands

Dogs with anal gland problems, such as an impaction or infection, are known to excessively lick and bite at the area. Their anal glands contain a gland fluid that is involuntarily expressed when a dog poops. When dogs have issues with their anal glands, they can become painful, and dogs may try to find relief by licking at them.

However, anal gland fluid has a potent fishy smell that can make a dog’s breath smell foul after licking.

If you’re concerned about your pet’s well-being, we recommend you contact a veterinarian.

Did you know you can talk to a vet online? Click on the image or button below to schedule a call: PangoVet_Mention-in-Content Savings V1


divider dog paws 4 oct 2024

Conclusion

There are several possible reasons behind your dog’s bad breath, such as dental issues, certain diseases, and dietary habits. It’s normal for dogs to have a mild odor from their breath but usually isn’t very unpleasant to smell. If you want to get your dog’s breath smelling fresh again, it’s important to find the underlying cause of their bad breath.

You should also maintain your dog’s oral hygiene with regular brushing and having their teeth professionally cleaned.

Also see:


Featured Image Credit: Neal Bryant, Shutterstock

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

10 Pet Obesity Statistics Know in 2025: Dogs, Cats & Other Pets

Note: This article’s statistics come from third-party sources and do not represent the opinions of this website. Pet obesity has skyrocketed in recent...

National Australian Shepherd Day 2025: What Is It & How to Celebrate

The Australian Shepherd is the farmer’s herding dog of choice. They are highly intelligent, energetic, and devoted companions; if you have ever owned...

Are Slow Feeders Good for Dogs? Vet-Reviewed Purpose & How to Use Them

Does your dog practically inhale their food? If so, you may want to consider a slow-feeder dog bowl. Slow-feeder bowls are designed to...

How to Get Dog Poop Smell & Stains Out of Shoes: 5 Effective Ways

There is nothing more frustrating than getting dog poop on your shoes. Needless to say, the stench is downright awful, and no matter...

More related

11 Vet-Verified Great Pyrenees Facts That You May Not Know

Great Pyrenees are beautiful and amazing dogs that have coexisted with humans for many years. While they’re most recognized for their large size...

How to Stop Your Dog from Biting the Leash: 9 Vet-Verified Tips

Of all the undesirable behaviors our dogs can present, leash-biting can put one of the worst dampers on the daily routine. Walks become...

10 Disheartening Canada Dog Fighting Statistics to Know in 2025

Note: This article’s statistics come from third-party sources and do not represent the opinions of this website. Dog fighting is a heinous and...

Corgi vs Chihuahua: The Key Differences (With Pictures)

Chihuahuas and Corgis originate from opposite sides of the world, and their differences don’t end there. Tiny Chihuahuas hail from Mexico, where they...

Keep reading

5 Ollie Dog Food Alternatives in 2025: Comparison & Reviews

When it comes to your dog’s health, Ollie pet food is one fresh-food brand that is becoming increasingly popular. This brand is on a mission to feed dogs with only the best and freshest ingredients available. Unfortunately, as they grow...

dog eating wet food

Can Dogs Eat Bay Leaves? Vet Approved Facts & FAQ

Dogs often have a way of charming their way to eating their humans’ table food. While many of us find them irresistible and often give in, feeding them scraps of our own food, it’s important to know if the food...

Can Dogs Eat_bay leaves

Can Dogs Eat Hemp Seeds? Vet-Verified Facts & FAQ

There are many highly nutritious superfoods on the market that we add to our diets daily, and we may consider doing the same for our dogs. Hemp seeds are a popular human superfood, and hemp-based products are now thriving in...

Can Dogs Eat_Hemp Seeds

Can Dogs Eat Grapes? Vet-Verified Risks & Safety Guide

Can dogs eat grapes? To many canines, any food left out and in their reach is for them. They don’t stop to consider whether it should be for them, which is why owners must be vigilant to ensure their pets...

Fresh red grapes on the table

Vitamin K for Dogs: 5 Vet-Approved Food Sources

Vitamin K is a necessary nutrient for all humans and animals. In addition to making this vitamin within our bodies, we can get the vitamin from the foods that we eat, and so can your dog! Here are five great...

white samoyed dog looks at a plate of vegetable salad

Victor Dog Food vs Purina Pro Plan: 2025 Comparison, Pros & Cons

With so many pet foods on the market, it can be daunting to choose the right one for your dog. Naturally, we want the best for our pups, but the sheer number of brands, ingredients, options, and more can lead...

Dogster_Dog Food Victor VS Purina Pro Plan

Can Dogs Eat Enchiladas? Vet Approved Nutrition Facts & FAQ

Enchiladas are a popular and delicious Mexican dish that many people worldwide adore. Most people love this dish and your pets may also want to get a taste. The smell of meat and seasonings may cause your dog to beg...

Can Dogs Eat Enchiladas

5 Best Sources of Iron for Dogs (& How Much They Need Daily)

Many lifeforms need iron to survive, from wild animals like giant blue whales and African lions to domesticated pets like dogs and cats. Iron has many important qualities, so it’s abundant in different sources of food. Most commercial dog food...

Siberian husky-dog-puppy-eating-a-meat_Hyper-Set_shutterstock