8 Reasons Why Cat Poop Smells So Bad and How to Get Rid of the Smell (Updated 2026)
Last updated: October 22, 2026.
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- Cat poop always has an odor, but it should not stink up the whole house. A sudden change in smell is worth noticing.
- Common causes are diet, food sensitivity, parasites, gut inflammation, stress, medications and a dirty litter box.
- Call your vet right away for blood, black or tarry stool, liquid stool or if your cat seems unwell or lethargic. A metallic smell can mean blood.
- For the odor in the house, daily scooping, a clean box and the right litter make a big difference.
Cat owners know the moment: you walk into the room and the litter box announces itself. A little smell is normal, since cats are carnivores and their waste is high in protein. But if the odor is overwhelming, or has suddenly changed, your cat may be telling you something. This guide explains eight common reasons, what you can safely do at home and when to call your vet.
This article is general information, not veterinary advice, and the earlier statistics that appeared in the original version have been removed because we could not verify them.
As an Amazon Associate I earn from qualifying purchases.
8 Reasons Cat Poop Can Smell So Bad
1. Diet
Cats are obligate carnivores and eat a lot of animal protein, which makes their stool smellier than that of plant-eating animals, according to Cats.com. If the diet is hard to digest or not well balanced, the stool can smell worse, Great Pet Care says. If the stools are only a little “whiffy,” Cats.com suggests gradually changing to a high-quality diet and asking your vet before adding any supplements.
2. Food sensitivity
Great Pet Care notes that food allergies, most often to beef, fish or chicken, can cause gut inflammation and foul-smelling stool. Your vet can guide a diet trial, so do not guess.
3. Inflammatory bowel disease and other digestive conditions
PetMD says very smelly stools usually mean something is out of balance in the digestive system, anywhere from not tolerating the diet to inflammatory bowel disease or pancreatitis. Liver or gallbladder disease can also cause bad-smelling poop, according to Great Pet Care.
4. Parasites and infections
Intestinal parasites such as Giardia, coccidia and Tritrichomonas can inflame the intestines and cause smelly, loose stool. Great Pet Care notes these may need special testing and long treatment. Some of these organisms can spread to other pets and even people, so good hygiene matters and a vet check is the best next step.
5. Stress
Stress can upset a cat’s gut. Great Pet Care lists events such as a move or being picked on by another cat as examples. If the smell started after a big change, mention it to your vet.
6. Medications and supplements
Some medicines and even vitamin supplements can change stool odor, says Cats.com. Do not stop a prescribed medicine on your own. Ask your vet.
7. Hunting and eating prey
Cats that hunt and eat small birds and rodents tend to produce smellier stool, Cats.com notes. If your cat goes outdoors, that may be the reason, and prey can also carry parasites.
8. A dirty litter box or old plastic box
Cats.com points out that remnants of waste can become ingrained in a plastic litter box over time. San Diego Humane Society recommends boxes be scooped daily, fully cleaned about once a month and replaced when waste builds up on the bottom, usually every six months to two years.
When to Call the Vet
PetMD says to call your vet right away if the stool contains blood, is black or tarry, is pure liquid, or your cat seems unwell or lethargic. A metallic smell can mean iron from blood. If your cat strains, has diarrhea that lasts or loses weight or appetite, see a vet as well. If the stinky poop is just one or two episodes in an otherwise healthy cat, Cats.com says it is usually not a cause for concern.
How to Reduce Litter Box Odor
While you sort out the cause, you can keep the room fresher. The Animal Humane Society advises scooping solid waste and clumps daily, washing the box with warm water and soap at least once a month and using plain, unscented clumping litter. Aim for about two inches of litter, and provide one box per cat plus one. Do not use strong disinfectants because they can put cats off.
Litter Picks Buyers Like for Odor
These are popular clumping litters that buyers say control odor well. We have not tested them. Our full comparison is in Best Cat Litter for Odor Control.
Many long-time buyers say it makes hard clumps and is lower in dust than other clay litters. Some say it creates fine powder as the granules break down, so scoop often. It is unscented, which suits cats that dislike fragrance.
See Dr. Elsey’s on Amazon →As an Amazon Associate I earn from qualifying purchases.
Reviewers, especially those with automatic litter boxes, report strong odor control, low dust and clumps that slide out cleanly. It costs more than some clays, and a few buyers find the scent strong.
See Arm & Hammer Slide on Amazon →As an Amazon Associate I earn from qualifying purchases.
Frequently Asked Questions
Is smelly cat poop normal?
Some odor is normal. PetMD says the smell of normal stool should be limited to the area around the litter pan after a few minutes. A stool that suddenly becomes much more pungent is a reason to watch closely.
Should I give my cat probiotics or fiber?
Ask your vet first. Supplements can change stool odor and the cause of the smell may be a medical problem that needs testing.
Does a better litter fix the smell?
It can help with the odor in your home, but it will not fix an underlying digestive problem.
Related Guides
- Best Cat Litter for Odor Control
- Best Cat Litter Mats
- Best Enzyme Cleaners for Pet Accidents
- Foods Your Cat Should Never Eat
Sources
- PetMD, “What Should My Cat’s Poop Look Like?” (https://www.petmd.com/cat/general-health/what-should-my-cats-poop-look-like)
- Great Pet Care, “Why Does My Cat’s Poop Smell So Bad?” (https://www.greatpetcare.com/cat-health/why-does-my-cats-poop-smell-so-bad)
- Cats.com, “Why Does My Cat’s Poop Smell So Bad?” (https://cats.com/why-does-my-cats-poop-smell-so-bad)
- Animal Humane Society, “Preventing and solving litter box problems” (https://www.animalhumanesociety.org/resource/preventing-and-solving-litter-box-problems)
- San Diego Humane Society, “Litter Boxes 101” (https://sdhumane.org/resources/litter-boxes-101/)
- Amazon customer reviews for the litters above, read October 22, 2026
This article is general information for pet owners, not veterinary advice. If your pet seems sick, or you are unsure, call your veterinarian.
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