Colin FosterBy Colin Foster

Updated November 2026

A cat that smells bad is usually dealing with one of a few common causes: dental disease, anal gland problems, poor grooming, a dirty litter box, skin infections, or an underlying health issue. Most of these are easy to check, and many are fixable at home. If the odor is new, strong, or paired with other changes, your vet should take a look.

Common Reasons Your Cat Smells Bad

Cats are famously clean, so a sudden odor is worth paying attention to. The most frequent source is the mouth. Periodontal disease, tartar buildup, and infected gums produce a sharp, rotten smell that often shows up on the breath first. Bad breath in cats is rarely just “normal cat breath.”

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Anal glands are the second big suspect. These two small sacs sit on either side of the anus and normally empty during bowel movements. When they fail to empty, they can become impacted or infected, leaving a fishy or oily smell. You may notice your cat scooting, licking the area, or chewing at the base of the tail.

Skin and coat problems come next. Overweight cats, seniors, and cats with arthritis often cannot reach their lower back or hindquarters, so grease, urine, and debris build up. Yeast and bacterial skin infections also cause a musty smell, especially in skin folds.

Factors That Make the Smell Worse

Litter box habits matter more than many owners expect. A box scooped once a week, or a litter that traps urine odor, can make the whole room smell, and that smell can cling to a cat’s fur if it walks through it often. Cats that stop using the box may also be urinating outside it. For help with that, see Why Cats Stop Using the Litter Box and How to Respond.

Diet plays a role too. Some cats produce stronger-smelling stool or gas after a sudden food change, and a cat with digestive upset may have more noticeable odor. A change in appetite can also signal a health issue, so Why Your Cat’s Appetite Has Suddenly Changed is worth reading if your cat is also eating differently.

Health conditions can cause a distinct smell. Diabetes can make breath smell sweet or fruity, and kidney disease often causes a strong, ammonia-like breath. Urinary tract infections can make urine smell stronger than usual.

How to Fix It at Home

  1. Check your cat’s mouth. Look for red or swollen gums, brown tartar on the teeth, or a foul breath that lingers.
  2. Look at the rear end. Check for redness, swelling, or scooting. Do not squeeze the anal glands yourself unless your vet has shown you how.
  3. Groom your cat regularly. Brush short-haired cats weekly and longer-haired cats several times a week, and wipe any soiled areas gently with a damp cloth.
  4. Scoop the litter box at least once a day and fully change the litter on the schedule the manufacturer recommends.
  5. Keep the food bowl and water dish clean, and wash bedding in unscented detergent.
  6. Schedule a vet visit if the smell is strong, new, or paired with weight loss, vomiting, drinking more, or changes in urination.

Dental disease in particular rarely gets better without a professional cleaning, so if the breath problem persists after brushing and diet changes, ask your vet about a dental exam. This is a health issue, and a vet should confirm the cause before you treat it.

What We’d Use

A cat-safe enzymatic cleaner is useful for breaking down urine and odor in the litter area and on bedding, and it is a good first step when the smell is coming from the environment. View on Amazon

For grooming a cat that cannot keep its coat clean on its own, a soft rubber grooming brush helps lift loose hair and debris from the skin. View on Amazon

FAQ

Can I bathe my cat to get rid of the smell?

Most cats do not need regular baths, and many dislike them. Bathe only when your cat is soiled, and use a cat-specific shampoo. If the smell comes from the mouth or rear end, bathing will not fix the cause.

Is it normal for a cat’s breath to smell a little?

A faint, slightly meaty smell can be normal. A strong, rotten, or persistent odor is not, and usually points to dental disease or another health problem.

When should I call the vet about a smelly cat?

Call your vet if the odor is sudden, very strong, or comes with drooling, pawing at the mouth, weight loss, vomiting, or changes in urination. Your vet can check for dental disease, infection, and metabolic conditions that a home check cannot rule out.

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Colin Foster

About Colin Foster

Colin Foster is part of our editorial team and reviews and edits our cats guides, checking product details against manufacturer specifications and owner feedback.