Bad Breath in Cats and Dogs

Pomeranian dog
Pomeranian Dog, Image Courtesy of SOMMAI,

Before jumping to the conclusion that bad breath means that a pet is ill, owners should keep in mind that an animal’s breath will probably never smell minty fresh. However, an extremely strong odour can signify a medical problem.

Causes of Bad Breath in Dogs and Cats

Pets may develop bad breath because they suffer from gum disease or a more serious illness. Curing bad breath in cats and dogs requires determining the cause and treating it. This may involve removing a foreign object, treating tumours or infections, tooth extraction, making dietary changes, or just having a veterinarian thoroughly clean the teeth.


Gingivitis (gum disease) is the most common cause of bad breath in pets. In addition to halitosis, symptoms of gum disease include:

    • Brown tartar on teeth
    • Mouth pain/difficulty eating
    • Drooling
    • Inflamed red gums

According to Drs. Foster and Smith, 70% of cats and 80% of dogs develop gingivitis by 3 years of age. When a pet has gingivitis, the bacteria that infest the gums may enter the bloodstream and eventually attack other organs, leading to heart or kidney disease, so it’s important to treat the problem as soon as it’s noticed, or better yet, engage in preventative dental care.

Other problems that can cause bad breath include oral abscesses, ulcers, or tumours; foreign bodies stuck in the mouth (plant material, bone, hair, etc.); and various infections. In addition, eating garbage or feces is a common cause of bad breath in dogs (this problem is rare in cats).

Diseases That Cause Bad Breath in Cats and Dogs

There are a number of serious diseases that can cause bad breath in cats and dogs. These include:

    • Liver Disease – In addition to foul breath, symptoms may include vomiting, a slight yellow tint to the corneas and gums, and lack of appetite.
    • Kidney Disease – Breath may smell like urine and the cat or dog will drink and urinate more often than in the past.
    • Diabetes – Additional symptoms may include breath that smells fruity or sweet, drinking and urinating more frequently than normal, and a ravenous appetite.

Young cats with bad breath and dental disease may be suffering from feline immunodeficiency virus (FIV) or feline leukemia virus (FeLV), though a variety of other infections may also cause bad breath in cats and dogs. In addition, problems within the respiratory system or gastrointestinal tract may cause bad breath.

When in doubt, take your pet in for a veterinary check-up to rule out serious illness, especially if there are symptoms such as lethargy, bloody oral discharge, increased urination and thirst, change in appetite, diarrhea, or vomiting. If your pet has a clean bill of health, there are some remedies you can try.

Remedies for Bad Breath in Cats and Dogs

Dental Care

There are toothbrushes that fit over a finger and flavoured pastes formulated especially for pets. A children’s toothbrush can also be used, but don’t use toothpastes designed for people – they can make pets sick because animals don’t spit out the paste.

Chlorhexidine sprays, available from veterinarians and pet supply stores, can also be sprayed on a small toothbrush and applied to a pet’s teeth without actually brushing to help to reduce bacteria and dissolve plaque. They are not as effective as regular tooth brushing, but better than nothing.

Dental Treats 

A number of companies have developed treats designed to remove tartar or freshen breath. According to Fraser Hale of the World Small Animal Veterinary Association, studies have shown the efficacy of C.E.T. Forte Cat Chews in gingivitis reduction for cats and Pedigree Dentabones for dogs. Veterinarian Ron Hines recommends C.E.T. Chews and IAMS Tartar Treats.

Dental treats should be considered a supplement to dental care, not a replacement for it. Check with your veterinarian before providing dental treats if your pet suffers from a medical condition or is on a special diet (hypoallergenic, calorie-reduced, etc.).

Breath Fresheners 

There are drops and gels available for reducing or eliminating bad breath that can be sprayed, applied manually, or added to water or food, depending on the product. Some claim to kill plaque and help keep teeth clean as well. However, if there is an underlying medical problem, breath fresheners will just mask it, so checking with your veterinarian before using these products is recommended.

Bones and Chew Toys 

Chewing bones or chew toys can help prevent tartar build-up, particularly if started when pets are young. However, small bones such as those from chicken or fish are dangerous as they can splinter and are easily swallowed. If providing bones, choose heavy shank and shin bones that can’t be swallowed, but keep in mind that pets chewing bones or hard rawhide items risk tooth fracture. Supervising pets while they chew on rawhide or bones is recommended.

There are plenty of softer chew toys designed for dogs and cats. The World Small Animal Veterinary Association recommends Dr. Ballard’s Chew-eez rawhide strips (now sold under the Purina label) as among the safest products on the market. As for other chewables, the Association expresses concerns about Pigs’ ears, which may harbour pathogens, and dental rings (paperboard covered in mint flavour, colouring, and ground bone), because no studies have been conducted into their safety or efficacy.

Dental Diets 

Some veterinarians recommend feeding a dry food rather than canned to reduce tartar on teeth. However, others have expressed concerns that such diets can lead to chronic low-level dehydration and urinary tract problems. Also, many dry foods are high in carbohydrates and relatively low in protein, putting pets at risk for diabetes and other serious health problems.

If feeding dry food, be sure to choose a high-protein food in which real meats (not grains or by-products) comprise at least the first two items on the ingredients lists, and provide bowls of water at multiple locations throughout the house to encourage more drinking.

There are specialty dental diets designed to scrape plaque from teeth. Although these tend to be too carb-heavy to feed as an exclusive diet, some dental kibbles can be mixed in with a higher-protein dry food to aid in plaque removal.

Please note that this article is not intended as a substitute for veterinary care and consultation. Medical concerns should be referred to a qualified veterinarian.

For more cat articles, see the main Cats page. For more dog articles, see the main Dogs page.


    • Drs. Foster & Smith. (2010). “Cat Dental Facts” and “Dog Dental Facts.”
    • Hale, F., World Small Animal Veterinary Association. (2001). “Homecare Products and How They Work.” Veterinary Information Network,
    • Feline Advisory Bureau. (n.d.). “Mouth Problems in Cats.”
    • Hines, R., DVM, PhD. (2009). “Why Does My Cat or Dog Have Bad Breath?”
    • Primovik, D., Dr. (2010). “Halitosis (Bad Breath) in Cats” and “ Halitosis (Bad Breath) in Dogs.”
    • (n.d.). “Bad Breath in Cats” and “Bad Breath in Dogs.”

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