Kitten Diarrhea: Causes and How to Stop It

Kitten diarrhea may not be the classiest of convos, but it's one of the most common issues seen by vets. For the majority of these cases, it's just a one-off response to a sudden change in their environment. However, if prolonged, it can be a sign that something else is up. Even so, diarrhea is usually an easily treatable condition, so don't panic!


  • What is kitten diarrhea
  • Why are kittens more susceptible to diarrhea than cats?
  • What are the common causes of kitten diarrhea
  • How to work out what the cause is
  • Kitten diarrhea colour chart
  • When to contact your vet
  • What to feed a kitten with diarrhea

What is kitten diarrhea

We won't get too graphic here, but diarrhea is essentially a watery, loose poop. There are two types, acute and chronic, with the former being a sudden onset and the latter lasting for over 3 weeks. Kittens (like puppies) are renowned for having dicky tummies now and again as they develop their immune system and get accustomed to new things. So it's generally not something to be too concerned about and not a disease. It is however something to monitor as diarrhea is a symptom of something... Diarrhea can present on its own or along with other symptoms. We'll discuss some of these later on.

Why are kittens more susceptible than cats?

Kittens are not only the cutest little balls of floof in the world but the most delicate and sensitive floof-balls. Their immune system is still developing, which makes them more susceptible to illnesses than adult cats. In part this is because their gut, where 70% of their immune system is located, hasn't had time to fully colonise and diversify with bacteria. That's why we offer probiotic kitten food and prebiotic kitten food to help support healthy gut flora.

On top of this, kittens are eagerly trying to understand their new world. This means lots of eating and licking things they probably shouldn't and adventuring into places they shouldn't.

Kitten eating

Common Causes of Kitten Diarrhea

The first thing that tends to spring to pet parents' minds when their kitty has diarrhea, is that it's because of their food. However, food isn't necessarily the cause, it's much more likely down to one of these factors:

1) Environmental Factors

There are several environmental factors that could be to blame, including allergies, climate, and environmental change. Any sudden environmental change like moving house, changing their routine, or getting a new pet can all trigger stress, and consequently diarrhea. Equally, if a kitten moves to a new climate or the weather suddenly becomes much warmer, they may get heatstroke and or dehydration, another possible cause.

Finally, pollen or other environmental allergies can trigger diarrhea. Have you noticed that your kitten's diarrhea comes on seasonally, or when you started using different cleaning products? This is a clear cue that it's down to something environmentally.

2) Drinking Cows Milk

Tom does it, the Aristocats do it, I mean Puss in Boots even downs pints of cows milk on the reg. However, cats shouldn't drink milk as they can't digest it. This is because our kitties lack the enzyme lactase to digest the lactose in milk. Yes that's right our kities are lactose intolerant. Before you reach for lactose-free milk, know that cow's milk has no nutritional value for our feline friends so we recommend steering clear fully. It's a common misconception that dairy is fine for our cats with meowmies feeding cows milk, yoghurt and cheese as a treat, which leads to diarrhea.

3) Ingesting Something Toxic or Hazardous

As we mentioned your little explorer loves using their mouth to identify foreign objects. This means they're more likely to ingest a toxic substance (like antifreeze) or hazardous object (like a bone that can cause intestinal blockage). We know kittens who've managed to eat everything from hair bands to twigs to their litter, so you really can't let the little nutters out of your sight. Along with keeping watch, to help prevent your young cat from harming themselves ensure you thoroughly lock away any cleaning products, and avoid having any non-cat-friendly plants. If your kitty has eaten something funny, diarrhea will likely be accompanied by vomiting. Get in touch with your vet and let them know exactly what your kitten has got ahold of.

4) Infection or Parasites

Bacterial and viral infections that can cause diarrhea include; salmonella, campylobacter, ecoli, feline immunodeficiency virus, feline leukaemia virus, and giardia. Kittens are more likely to catch these if they're surrounded by other animals. That's why it's important to keep them inside until they've had all their kitten vaccinations and are ready to battle the outside world. You'll know if this is the cause, as other symptoms like blood or mucus may be present in the stools. Bacterial infections are much more common if your kitten is eating a raw diet, which is why the majority of vets and the PDFA advise against this.

As well as bacterial or viral infections, diarrhea could be down to parasites like hookworms or roundworms. These rather ugly little beings live in kittens' intestines and feed on their intestinal content. Often having been caught from their mother's milk or the environment. These can be prevented by ensuring your kitten is dewormed at two, four, six, and eight weeks and regularly thereafter.

5) Changes In Diet

Just as changes to their environment can be a trigger, so can change in their diet. This includes feeding the incorrect quantity, transitioning to a new food too quickly, or changing the type of food they eat, e.g. moving to one that's much richer. Food intolerances (besides lactose) are often thought of as a cause, however, these are rare (allergies even more so) in kittens so unlikely to be the trigger.

We always recommend transitioning onto a new food for a minimum of two weeks for kittens. Doing so by gradually increasing the portion of your new kitten food to their old one until you reach 100%. During this time changes to their stools or flatulence are common and nothing to worry about, as long as they subside after the transition period. You should also recalculate their feeding amount every time you move on to new food and as your kitty grows and changes in weight. Every brand of cat food and recipe has a different nutritional content and therefore feeding amount. Don't forget kittens should be fed small meals several times a day, so overfeeding is one of the common dietary causes of upset tums.

If you're feeding the exact same food and quantity and your kitten suddenly has bouts of diarrhea, you should rule out food as the cause, and explore one of the previously mentioned reasons. Keep your vet up to date with any changes to get the best advice to calm your kitties tum.

How to work out the cause?

If it's not obvious what the cause is, there are two ways to help you identify it. First it's important to understand what other symptoms are apparent. Secondly, use a kitten version of the Bristol Stool Chart. Here's one we made earlier:

Kitten Diarrhea Colour Chart

kitten diarrhea

When to contact your vet

If your kitten has diarrhea but acts normal, aka is still playing, eating, and drinking, closely monitor them and as long as it doesn't last longer than 24 hours it should be okay. If in doubt call your vet!

If your kitten's diarrhea is combined with symptoms like blood in their stools, loss of appetite, vomiting, rancid-smelling breath, a fever, or dehydration, contact your vet immediately. They'll likely ask you to bring a stool sample with you to help them identify the issue and provide the right treatment. This may include anti worming medication, anti-parasitic meds, or antibiotics.

What to Feed a Kitten with Diarrhea

If you don't need to see the vet as your kitten has no other symptoms, you can help settle their tum by:

  • Feeding a plain diet, like boiled chicken and white rice
  • Opting for smaller more frequent meals
  • Avoiding rich and fatty food, and steering clear of extras e.g. cat treats
  • Providing water to prevent dehydration and monitoring their consumption (this should be done anyway)
  • Slowly reintroducing their normal diet

If after 24 hrs you've seen no improvement, speak to your vet

We hope these tips help your kitten return to their perfectly strange selves and do pretty poops once more!

Whilst you're here, why not read:

  1. When can kittens go outside?
  2. Kitten Vaccinations
  3. How to litter train a Kitten
  4. Let's Talk About Feeding a Kitten

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