Diarrhea in kittens can be caused by a variety of factors.

While some of the causes themselves are more serious than others, diarrhea itself can be dangerous for kittens.

Treatment should always be sought especially if it is happening frequently over a short period of time.

Stress as a Cause of Diarrhea in Kittens

If you just brought this brand-new kitten into your home, or recently got a new pet, or another big change has happened recently in your kitten’s life, this could be the issue.

Keep an eye on her to make sure this is an isolated incident. If she keeps having diarrhea, or if it appears black and tarry, see the vet right away to rule out illness.

Dietary Changes

Another cause of diarrhea in kittens is a change in diet. This can happen when kittens are being weaned onto solid food after nursing from their mom, or if you changed their diets suddenly.

If you are switching them to a new brand of kitten food make sure you make that change gradually.

If you just adopted a kitten from a shelter and don’t know what she was eating there, the adjustment to a new food and the stress of a new environment can wreak havoc on her delicate digestive system.

In addition, if you have given your kitten some bit of a “treat” like cow’s milk or a rich piece of meat, this can temporarily cause her digestive upset as well and lead to diarrhea in kittens.

Toxins that Cause Diarrhea in Kittens

One thing that must be ruled out as a cause of diarrhea in kittens is household poisons and toxins.

Make sure you don’t have any dangerous houseplants for her to chew on. Check all the leaves and stems of your plants to make sure they haven’t been nibbled on.

If you recently washed a tub or counter top with bleach or other toxic substance, she may have walked on the surface and then licked her paws.

And make sure she hasn’t been in the garage where she could possibly lick up some antifreeze–this tastes good to animals but is highly toxic.

If you suspect she has gotten into any of these, and especially if she is exhibiting other symptoms along with the diarrhea such as vomiting, dry-heaving, or frothing at the mouth, get her to the emergency vet right away.

Parasites as a Cause of Kitten Diarrhea

diarrhea in kittensProbably the most common cause of diarrhea in kittens, next to dietary changes, is an internal parasite.

Of these, worms are the most common, especially roundworms. Roundworms are usually passed down from the mother, and will give your kitten a “pot-bellied” appearance.

Other worms that can be found in kittens are whipworms, hookworms, and tapeworms. These can cause diarrhea, vomiting, and a lack of appetite.

Luckily, worms in kittens are also easy to treat by your veterinarian.

If you notice bloody diarrhea or dark, tarry stool, this could indicate the presence of Giardia or Coccidia. Again, only your veterinarian will be able to confirm and treat this condition.

Oftentimes the presence of worms or other parasites doesn’t leave any obvious side effects.

Whenever you get a kitten whose veterinary history is unknown, or if she has been around other animals in a shelter, she must go to the vet for vaccinations, worming medicine, and anything else your vet recommends.

Worms are incredibly common in kittens, and are often treated just as a matter of course.

Other Diseases

The most disheartening cause of diarrhea in kittens is the presence of a disease.

The most common ailment that causes kittens and cats to have diarrhea is feline leukemia, or FELV.

This disease is easily preventable with several rounds of kitten vaccinations, but once transmitted it can be deadly.

It is possible for cats to live relatively comfortable lives with leukemia, but prevention is the best course of action.

To prevent your kitten from getting FELV, make sure she doesn’t spend time outside exposed to other animals until she has received all the necessary vaccinations.


Basically, the causes for diarrhea in kittens can be just about anything!

This is a frustration for kitten owners and veterinarians alike. This is why your vet will ask you many questions about possible household dangers, exposure to toxins, change in diet or environment, and other symptoms.

Most of the time, with veterinary treatment diarrhea in kittens will be cured.

With all the possible causes of diarrhea in kittens, however, veterinary intervention should be sought if it happens more than once.

For more information, see Treating Kitten Diarrhea.