Bad breath in dogs is an abnormal or foul smell emanating from a dog’s mouth. Bad breath or halitosis in dogs is caused by multiple factors that affect oral health, such as plaque buildup, tooth decay, tooth abscess, tooth fracture, gingivitis, mouth cancer, and aging. 

Bad dog breath is typically associated with oral problems, but systemic diseases that affect the liver and kidneys cause bad breath in dogs, too. A veterinarian diagnoses the cause of dog bad breath by oral cavity examination and laboratory tests. The standard treatment for bad breath in dogs is professional dental cleaning, although the exact treatment depends on the underlying cause. 

Why Does My Dog Breath Stink?

Your dog’s breath stinks because of the proliferation of bacteria inside the mouth. A dog has bad breath when there is a lack of proper oral hygiene, such as tooth-brushing, lack of nutritious food, and regular toy cleaning. Bacteria leads to plaque build-up, progressing into tartar, a hard mineralized substance that adheres to the teeth. Tartar increases the risk of tooth abscesses, cavities, tooth fractures, and gingivitis, contributing to bad breath. Dogs with bad breath and otherwise healthy teeth and gums require examination to diagnose systemic diseases such as kidney disease, liver disease, and diabetes. 

How common is Bad Breath in Dogs?

Bad breath in dogs is very common, and 80-90% of dogs experience periodontal disease. Periodontal disease is inflammation and infection of the tissues around a dog’s teeth, which is why the dog's breath stinks. “80-90% of dogs over the age of 3 have some component of periodontal disease”, according to the Cornell Richard P. Riney Canine Health Center. Dental disease affects “up to 90 percent of dogs over the age of two,” according to the World Small Animal Veterinary Association Global Dental Guidelines. 

What Causes Bad Breath in Dogs?

The causes of bad breath in dogs are listed below. 

• Dental Health Issues: Dental health issues are diseases that affect the oral cavity, which includes the lips, teeth, gums, tongue, and buccal mucosa, and is one of the leading dog bad breath causes.
• Kidney Disease: Kidney disease comprises conditions that lead to renal impairment through direct kidney injury or secondary injury from a primary disease that causes bad breath.
• Diabetes: Diabetes (Type II) is abnormally high glucose levels in the blood due to inadequate insulin production, causing acetone-like breath in dogs.
• Liver disease: Liver disease is any condition that damages the hepatic tissue through direct injury or toxicity, causing bad breath from toxin buildup in the body.
• Oral tumors: Oral tumors are abnormal tissue growths inside the oral cavity that cause bad breath due to infection or bleeding at the site. 

1. Dental Health Issues

Dental health issues are the most common dog bad breath causes. Incorrect dental hygiene leads to periodontal disease in dogs because of high oral bacterial loads. Plaque buildup is a common dental problem in dogs and progresses into painful gum inflammation and bleeding. The teeth are affected with caries that slowly eat away at the tooth , making the dog more susceptible to developing dental infections such as tooth abscesses and gum disease. Dental infections cause awful breath due to the enzymatic action of bacteria mixed with saliva, food particles, and blood. 

2. Kidney Disease

Kidney injury leads to a buildup of toxic metabolites in the body because a dog is unable to produce and excrete urine. The metabolic byproducts remain inside the body, causing ammonia. The ammonia accumulates and spreads in the blood. Ammonia has a distinct, pungent, and caustic smell that travels through the oral cavity, leading to bad breath. The scent is termed a “uremic” odor that is a hallmark of kidney disease in dogs.

3. Diabetes

Diabetes predisposes the dog to periodontal disease because saliva composition and production changes. The result of untreated diabetes in dogs is the compensatory breakdown of fat to provide energy for the body. The breakdown results in the production of ketones, which have a sweet smell similar to acetone. The ketones accumulate throughout the body and oral cavity and cause bad breath. 

4. Liver Disease

Liver disease affects the dog’s ability to filter toxins, chemicals, and drugs from blood. The toxins accumulate in the blood and circulate systemically, affecting bodily fluids and saliva. The bad breath smell caused by liver disease in dogs is very pungent and musky and is often accompanied by other systemic signs such as jaundice, wasting, and lethargy. 

5. Oral Tumors

The more common sites of oral tumors or neoplasia are the soft tissues such as the lips, tongue, buccal mucosa, and gums. The oral neoplasia  rupture, ulcerate, necrotize or cause infection and lead to bad breath in dogs. The common types of mouth cancer in dogs are melanoma, squamous cell carcinoma, and fibromas.

How is Bad Breath in Dogs Diagnosed?

Bad breath in dogs is diagnosed through examination and history-taking. The veterinarian asks for information regarding diet, age, and onset and duration of the bad breath. A full dental work-up includes ocular inspection of the mouth, radiographs, and blood exams, which check kidney, liver, and glucose function. Dogs undergo short-acting general anesthesia for the complete oral examination to prevent stress and facilitate mouth manipulation. Abnormal lumps are biopsied for laboratory evaluation of cellular makeup to distinguish the type of neoplasm. 

What Are the Symptoms of Bad Breath in Dogs?

The symptoms of bad breath in dogs are listed below.

• Gum swelling: Gum swelling or gingivitis is prevalent in dogs with bad breath. Gingivitis appears as swollen or puffy gums that are bright red in color. The dog typically has difficulty chewing or lack of appetite because of gum swelling and is a symptom of bad breath. 
• Bloody Saliva: Bloody saliva is an indicator of periodontal disease. Bleeding from the gums or mucosa is mixed with salivary contents causing the breath have a foul odor. 
• Discolored teeth: Teeth discoloration is a sign of plaque build-up. Plaque build-up leads to tartar formation over the teeth. Tartar and plaque are one of the leading causes of bad breath. 
• Cavities: Caries are areas of tooth decay over one or several teeth. The teeth have a black discoloration and are hurth when chewing. The bacteria present in the cavities mix with saliva and food particles that cause bad breath
• Ammonia smell: An ammonia-like smell is a foul smell that is similar to urine that has been exposed to air for several days. The uremic smell is an symptom of bad breath in dogs with kidney disease. 

How Can Diet Affect a Dog’s Breath?

Diet can affect a dog’s bad breath depending on the texture, ingredients, nutritional contents, and food quality. Food texture and make-up are important for mechanical cleansing and maintaining a healthy environment inside of the mouth. Raw, contaminated, and poorly prepared meals harbor harmful bacteria that cause gastrointestinal problems, leading to indigestion and stomach issues that affect the breath. Products, such as pet treats, contain high amounts of carbohydrates, which stay on the teeth unless they are cleaned. Carbohydrates in the teeth fuel bacterial growth, leading to dental disease. The Veterinary Oral Health Council (VOHC) provides a database of products that are proven safe and effective for use in dogs to prevent and help treat oral disease. 

Can Bad Breath in Dogs Indicate a Health Problem?

Yes, bad breath can indicate a health problem in dogs. Dogs in good health have little to no noticeable smell from the mouth, and bad breath is a sign of an underlying problem. Conditions such as tooth decay, tooth abscess, tooth fracture, cavities, gingivitis, oral tumors, and systemic disease are potential causes of bad breath in dogs. Failure to treat bad breath results in extensive damage to the oral anatomy and undiagnosed systemic diseases that require treatment. 

Are There Specific Dog Breeds More Prone to Bad Breath?

Yes, there are specific dog breeds that are more prone to bad breath. Brachycephalic dogs such as pugs, boxers, bulldogs, and shih-tzus have flat faces and short snouts, predisposing them to periodontal disease. The most common cause of bad breath in dogs is periodontal disease. 

Is Bad Breath in Dogs a Sign of Illness?

Yes, bad breath in dogs is a sign of illness. Bad breath in dogs is a symptom of an underlying disease that needs veterinary attention. Periodontal disease occurs in 80-90% of dogs older than two years old. Bad breath is highly associated with oral and systemic health and is an indicator of disease. Dog bad breath is a sign of potential kidney disease, diabetes, liver disease or oral tumors.

What are the Treatments for a Dog's Bad Breath?

The treatments for a dog’s bad breath are listed below.

• Regular toothbrushing: Poor hygiene causes bad breath in dogs. One of the simple treatments for a dog’s bad breath is toothbrushing with enzymatic toothpaste three times a week or more if the dog enjoys chewing. Plaque buildup is easily prevented by proper toothbrushing, preventing oral disease and bad breath. 
• Dental cleaning: A veterinarian performs a professional dental cleaning under general anesthesia to remove tough tartar. Tartar is hard and mineralized, requiring mechanical scaling to remove. Prophylactic dental cleaning once a year, starting at two years of age, is a good way to prevent and treat tartar from forming on the dog’s teeth. 
• Tooth extraction:  Severely decayed teeth with necrotic pulp require removal. Dental extraction requires general anesthesia administered by a veterinarian. The tooth is surgically removed, and the gums are stitched shut. The procedure removes necrotic bone and tissue and prevents further pain and infection. 
• Antibiotics: Abscesses are pockets of infection forming under the tooth. The treatment for bad breath caused by abscesses is extraction. Some abscessed teeth are too swollen and painful to be extracted safely, and antibiotics are used to reduce the infection prior to removing the tooth. Dental filling is an alternative treatment when the abscess is treatable. 
• Root Canal: A root canal procedure treats bad breath caused by pulp infection in salvageable teeth. The procedure is done under general anesthesia and involves drilling through the tooth until the pulp is exposed. The infected pulp is extracted, and the canal is thoroughly cleaned and then filled.

How can CBD products help get rid of Dog's bad breath?

CBD products can help get rid of dog’s bad breath by reducing inflammation, which calms and soothes dogs experiencing gingivitis and associated pain. CBD is especially beneficial for dogs with neoplastic dental disease as it has anti-cancer properties for neoplastic growth. A quality CBD oil product is made of high-quality hemp formulated by well-established manufacturers that provide third-party laboratory testing. 

How Effective Are Dental Treats and Chews in Controlling Bad Breath?

Dental treats and chews are moderately effective in controlling bad breath, depending on the ingredients. Look for VOHC-accepted products to identify and verify that they help control bad breath. Read the ingredients and claims of the products and look out for potentially harmful ingredients such as rawhide bones or hard bones and high amounts of synthetic preservatives and sugars. The underlying cause of bad breath requires medical attention to completely resolve the problem.

What Types of Food Can Cause Bad Breath in Dogs?

The types of food that can cause bad breath in dogs are listed below.

• Sugary food: Sugary food provides extra carbohydrates that oral bacteria require to thrive. A diet of sugar-dense food, such as too many fruits, treats, and human food coupled with a lack of dental cleaning results in plaque build-up and bad breath.
• Raw meats: A raw diet contaminated with bacteria such as Salmonella causes digestive issues. Salmonellosis occurs in dogs fed raw diets that are not meticulously screened and prepared. The digestive issues cause an imbalance in gut flora, which causes bad breath in dogs. 
• Spoiled food: Spoiled food is a breeding ground for dangerous bacteria and fungi. The pathogens cause digestive issues, including vomiting and diarrhea. Persistent vomiting causes bad breath by constantly introducing digestive enzymes, stomach acid, and digesta into the mouth. 
• Bones: Dogs eating bones are at risk of splintering in the mouth. Cooked and raw bones break into sharp shards and lodge in the mouth, causing lesions that bleed and become infected. Oral Infection causes bad breath in dogs. 
• Hard treats: Dogs' teeth are brittle with age and are unable to chew hard treats for long periods. Tough foods such as, jerky, dehydrated meats, or dense cookies  chip or crack the tooth. The fractured tooth is predisposed to dental infections and tooth abscesses, causing bad breath.

Can Probiotics Help Stink Breath in Dogs?

Yes, probiotics can help stink breath in dogs. Probiotics help restore and maintain a healthy gut and oral microbiome for dogs. The beneficial bacteria help prevent the progression of periodontal disease. Probiotics give the oral microbiome more healing time and faster recovery. Probiotics are adjunct therapy for dental caries and abscesses in human dental medicine.