Why Does My Cat Have Bad Breath?

What it usually means

Most bad breath starts in the mouth. Bacteria in plaque build up along the gumline, harden into tartar and inflame the gums, a condition called gingivitis. Left alone, that can progress to periodontal disease, which destroys the tissue holding the teeth in place. Cornell estimates periodontal disease affects about 85 percent of cats over six. Tooth resorption, where a tooth slowly breaks down from the inside, is also very common and painful.

Other mouth causes include stomatitis, a severe inflammation of the gums and mouth lining, broken teeth, a tooth-root abscess, something caught between teeth or under the tongue, and oral tumors in older cats. Outside the mouth, breath that smells like ammonia or urine can occur with kidney disease, and a sweet or fruity smell can occur with uncontrolled diabetes. Those are less common, but they are why a new change in breath deserves a checkup.

Other signs of mouth pain

Cats hide pain well, so bad breath is often the first thing an owner notices. VCA lists pawing at the mouth, head shaking, jaw chattering, drooling sometimes tinged with blood, dropping food, chewing on one side, and difficulty swallowing. Some cats start preferring soft food, eat more slowly, or go to the bowl, sniff and walk away.

Look gently at the gums if your cat allows it. Healthy gums are pink and smooth along the teeth. A red line at the gumline, swollen or bleeding gums, brown or yellow tartar and missing or broken teeth all suggest dental disease. A cat that stops grooming may also be in pain.

When to call your vet today

Book a visit promptly if your cat has bad breath plus drooling, bleeding from the mouth, swelling of the face or under the eye, or is dropping food or eating less. Facial swelling can mean a tooth-root abscess. Call the same day if your cat has stopped eating altogether, because cats who go without food for more than a day or two can develop serious liver problems.

Also call soon if your cat's breath smells of urine or ammonia, or is sweet and fruity, especially with drinking and urinating more, weight loss or vomiting. These changes can point to kidney disease or diabetes, both of which are far easier to manage when caught early.

When it's an emergency

Bad breath itself is not an emergency, but go to your vet or nearest emergency vet immediately if your cat cannot close the mouth, has a jaw injury after a fall, is bleeding heavily from the mouth, or is drooling and pawing at the mouth suddenly, which can mean something is stuck. Never try to remove an object from deep in the mouth or throat yourself.

Get urgent care too if your cat chewed an electrical cord, which can burn the mouth, or licked a chemical, a toxic plant or a caustic cleaner. For a possible poisoning, call ASPCA Animal Poison Control at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661 (a fee may apply). Lethargy with vomiting and very strong urine-smelling breath also needs prompt care.

What you can safely do at home

You cannot treat established dental disease at home, but you can stop it getting worse after your vet has dealt with it. VCA calls daily tooth brushing the most effective way to control plaque. Use a soft pet toothbrush or finger brush and a pet toothpaste. Never use human toothpaste, which is not meant to be swallowed and can contain xylitol, which is toxic to many pets.

Start slowly: let your cat lick the paste, then touch the teeth for a few seconds, building up over a couple of weeks. Do not scrape tartar off with metal tools at home, which scratches the enamel and helps plaque return faster. If your cat will not accept brushing, ask your vet about dental diets or treats carrying the Veterinary Oral Health Council seal.

What the vet will likely check

Your vet will examine the mouth, teeth and gums, check for swelling and pain, and ask about appetite, weight, thirst and litter-box habits. If they suspect illness elsewhere, they may run blood and urine tests to check the kidneys and blood sugar. That helps both to find the cause and to plan for safe anesthesia.

A full assessment of the teeth needs general anesthesia, because cats will not keep still for probing and many problems hide below the gumline. VCA recommends a complete oral exam with dental x-rays under anesthesia. During the same procedure, the teeth are cleaned above and below the gumline, and badly diseased or resorbing teeth are usually extracted, which often makes a cat noticeably more comfortable.

Prevention

Brushing several times a week, ideally daily, is the single best habit. Start when your cat is young if you can. Have your cat's mouth checked at every annual exam, and follow your vet's advice on professional cleanings; VCA says some cats need them every six to twelve months.

Consider products with the Veterinary Oral Health Council seal, which have been shown to reduce plaque or tartar. Watch for early signs such as a red gumline or changes in how your cat eats, and book a visit then rather than waiting for the smell to get worse. Keeping your cat at a healthy weight and up to date on checkups also helps catch kidney disease and diabetes early.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.