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Why Does My Cat’s Poop Smell So Bad? 8 Vet-Verified Reasons & Solutions

constipated cat in the litter box

As much as we all love our cats, cleaning out their litter trays is unlikely to top any cat lover’s list of favorite tasks. If your cat’s poop smells bad, this can make this job even worse!

Smelly cat poop can be a sign that something is wrong, so it’s important to get to the bottom of the problem, so to speak! So, if you’re asking yourself “Why does my cat’s poop smell so bad?” then keep reading, below we have eight of the common reasons why along with the stinky cat poop remedy.

First, though, if your cat’s stinky poop hasn’t freshened up after a couple of days, seek veterinary advice. If their bad-smelling poop is accompanied by vomiting or blood or has a diarrhea consistency, seek an emergency veterinarian.

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    The 8 Reasons Your Cat’s Poop Smells So Bad

    1. Cat litter

    Natural cat litters like paper, unscented clay, and wood pellets often hold onto the smell of cat poop, even after you have cleaned the tray. Your cat’s poop might not smell any worse than normal, but that lingering smell can soon become unpleasant.

    Solution

    Switch to a scented cat litter or one with odor control such as baking soda. You can also invest in a litter additive that helps keep pesky odors at bay. If you continue using unscented litter, it can help to clean them out as often as possible, as well as do a full litter change once or twice a week.


    2. Diet

    Introducing a new food to their diet can sometimes lead to smelly cat poop, often with a loose consistency. If you plan to change your cat’s diet without a specific medical reason for it, you should always try to do it gradually. You can change to the new diet over a period of 10 days by adding 10% of the new diet every day. This will allow your cat’s digestive system to adapt to the new diet.

    Your cat might have eaten something that disagreed with them, like a mouse or something else that they managed to catch. Cats are carnivores, but protein-rich foods can also cause smelly poop. Cats can develop intolerances to grains or sensitivity to any of the ingredients in a formula, both of which can cause smelly poop as a result.

    Solution

    Talk to a vet about changing your cat’s diet or eliminating certain ingredients to see if these may be the trigger for your cat. This problem will resolve by itself if your cat’s digestive system is not sensitive to any of the ingredients in the new diet. If the stinky poop problem continues for more than 48 hours after a dietary change, let the veterinarian know about this.

    orange cat eating on an orange bowl
    Image Credit: Okssi, Shutterstock

    3. Bacteria

    If your cat eats something that’s been contaminated with bacteria like E. coli or Salmonella spp., this may cause cat poop that smells bad, as well as indigestion, inflammation, and diarrhea. Some cats love to hunt for food (even if they don’t need to!), and eating rodents or birds can put them at risk of a bacterial infection.

    Solution

    If your cat’s smelly poop doesn’t return to normal after 48 hours, seek vet advice.


    4. Parasites

    Certain types of intestinal parasites can cause excessive gas, diarrhea, and stinky cat poop. Giardia, coccidia, and trichomonas infestations can all result in your cat’s intestines becoming inflamed, too.

    Solution

     Your vet may want to test your cat for parasites, and they will recommend an anti-parasite or worming program depending on the level and type of infestation.


    5. Digestive issues

    If your cat’s digestive system is unable to digest or absorb fats and starches within their diet, this can result in particularly stinky cat poop. The technical terms for these digestive issues are maldigestion and malabsorption. Cats can also suffer from specific food sensitivities and intolerances. All of these digestive issues can result in bloating, gas, and stinky cat poop.

    Solution

    A vet will need to run tests to determine if your cat is suffering from maldigestion or malabsorption, sensitivities or any other digestive issue and they will advise you on how to treat each one accordingly.

    cat ultrasound at the vet's clinic
    Image Credit: Libre, Shutterstock

    6. Medications

    Certain medications, including hormonal medication and pain relievers, can cause smelly poop. Some vitamin and mineral supplements can also cause cat poop that smells bad.

    Solution

    Speak to a vet to rule out the possibility of medications causing foul-smelling feces. Most cat foods these days are completely balanced when it comes to vitamins and minerals, so never add a supplement to your cat’s diet without speaking to a vet first.


    7. Anal gland infection

    If your cat’s anal glands become infected, they might not drain properly. This can result in a foul-smelling discharge that can end up covering their poop and elsewhere!

    Solution

    If you notice a foul smell that does not just seem to be confined to the litter box, ask a vet to check your cat’s anal glands. Your cat may need their anal glands to be manually expressed or drained or medication to clear up an infection.

    healthy vs blocked anal sacs glands
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    8. Not covering up their poop or pooping outside the litter tray

    Even if your cat’s poop is not any smellier than usual, if they’re not covering it up in the litter tray, then it’s going to start to smell bad. This may be a sign that the litter is hurting your cat’s paws, or they don’t like the texture or smell of the litter. Cats pooping outside the litter tray may be having trouble accessing a tray with high sides, or the tray is too small.

    Solution

    Try switching to a different brand of litter or offering your cat a tray with lowered sides or one that’s much larger. Ask a vet to check that your cat isn’t in pain. Cats who are stressed about a recent change in circumstances may also poop outside their litter tray.

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    When to See a Vet

    If your cat’s smelly poop is also diarrhea-like in consistency, it’s doubly important to get them checked by a vet as soon as possible. Ongoing or recurrent diarrhea can be the result of an underlying condition, like kidney disease, liver disease, or a hyperactive thyroid. The vet will need to run tests to determine the exact cause.

    If smelly cat poop is combined with lethargy, lack of appetite, or vomiting, call a vet as a matter of urgency.

    Always keep your cat’s litter tray as clean as possible, and monitor your cat’s poop so you can quickly tell if something is wrong. You may smell it before you see it, and that’s always a sign that something isn’t quite right!

    If your cat’s stinky poop is combined with other issues, like pooping outside the litter box, your cat may be suffering from an underlying health condition. Speaking to a vet as soon as possible is the best course of action.

    If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

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    Wrapping It Up

    Certain stinky poop problems can easily be solved by changing the type of litter that you use or adjusting your cat’s diet. Others may need medication and ongoing treatment. Whatever the issue, seeking advice from a vet is essential, and then you can start looking forward to a happier cat and a pleasant-smelling home once again!

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    Featured Image Credit: RJ22, Shutterstock

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