Why Does My Cat Have Diarrhea?

It's a question that usually follows an unpleasant discovery at the litter box (and is usually followed by the question of who will clean it up).

Cat diarrhea is not a disease or illness; it's how we refer to bowel movements that occur more frequently than usual, and are unusually soft or fluid. So it's a sign that something isn't right with your cat. And a legitimate reason to consult your veterinarian, who can help you determine the cause and treatment, and will not be offended by conversations about cat poop.


Cats can be very picky, both inside and out. Gastrointestinal upsets are a fairly frequent occurrence among our cat companions, and diarrhea is one of the most common expressions of that issue. Just ask anyone who has tried to "surprise" their cat with an abrupt change in the dinner menu, and got a surprise of their own in return…

Learn about Purina® Cat Chow® Gentle - specially formulated for easy digestion.

The cause of your cat's diarrhea dilemma can be simple, or more complicated. It can be a reaction to something your cat has eaten. Or eaten to excess. Eating a new food, people food, rodents or birds, or other stuff they shouldn't (such as foreign objects or toxic substances) can all give cats diarrhea. Making changes to your cat's diet should be done gradually. And if your cat goes outdoors, remember that any al fresco dining she does beyond her food dish can cause problems.

Diarrhea can even be a sign of an allergic reaction, or an inability to digest a certain food. For example, despite what we've all heard about cats and milk, many cats don't actually have the dietary enzyme that allows them to digest it properly. The result? More unpleasantness at the litter box.

Intestinal parasites such as tapeworms can also cause diarrhea. While a bulging stomach is a symptom, tapeworm segments in your cat's stool are a sure sign. A virus or other illness can also be the culprit. In these cases, a visit to your veterinarian should be your immediate next step.


If you find yourself with a feline diarrhea dilemma, what next? Start with these four steps:

  • Before anything else, contact your veterinarian. Remember, veterinarians are trained to know all about symptoms like diarrhea - and what to do next.
  • Keep an even closer eye on your cat. By nature, cats are experts at concealing sickness and injury.
  • Limit the cat's diet to only small amounts of water for 24 hours. (Consider it a 1-day diet for intestinal repair.) But make sure she's still drinking, since diarrhea can cause dehydration.
  • After 24 hours, give her only small servings of very bland food, such as cooked, skinless white chicken meat mixed with white rice.

If you still don't feel like the situation is improving, contact your veterinarian again. Also, if you see blood in your cat's stool, or suspect that she has eaten something dangerous that is causing the problem, don't wait 24 hours. Call your veterinarian immediately.

To prevent further contamination, make sure you clean any icky areas in or around your litter box, and on your cat.

With proper care and veterinary support if needed, you can usually give your cat (and yourself) fairly quick relief from her diarrhea issues. So that you can both get back to enjoying a cleaner litter box, and a healthier life.

If your cat's coat gets yucky from diarrhea, it may be time for a bath. Read "Giving Your Cat a Bath" to learn more.


  • Siegal M. The Cornell Book of Cats. 1989: 14, 232.
  • Brunner D. The Cat Owner's Manual. 160.
  • Shojai A. The Purina Encyclopedia of Cat Care. 1998:191, 197-200.
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