Diarrhea is unpleasant for a cat and it is often distressing to their human. The cat might not make it to the litterbox on time or they might step in the soft poop and leave poopy footprints all over. Nobody wants that scratch and sniff on their couch.

So what “qualifies” as diarrhea? Normal poop is a soft formed tube (like fresh play doh). Diarrhea will be poop with too much water … it can be the consistency of pudding, oatmeal, or water.

Not sure if your cat poop is diarrhea? Google the Purina Fecal Scoring Chart. It has pictures that should help you pick your cats poop out of the lineup.


Why do cats get diarrhea? There are many, many, many reasons …..

Infectious reasons … Kittens and outdoor cats are more likely to have parasitic diarrhea than indoor only cats. Parasitic causes of diarrhea are roundworms, tapeworms, giardia, coccidia, etc. Kittens can get roundworms from their mom. Cats who hunt can gets worms from birds, mice, etc. Fleas can carry tapeworms. Panleukopenia is a virus that causes diarrhea. It is usually fatal in the young and can be fatal in adults that are not vaccinated. Some bacteria can cause diarrhea. Salmonella is a contagious cause. Overgrowth of the cat’s normal bacteria (clostridium, etc.) can also be a factor.

Non-Infectious reasons …. Cats can have diarrhea due to IBD (inflammatory bowel disease), food intolerance / allergy, some plants if ingested (poinsettia, etc.), metabolic disease (hyperthyroidism, diabetes, etc.), cancer, renal disease, and liver disease.

If your cat has diarrhea for more than 1-2 days, OR if there is also vomiting / loss of appetite / lethargy, see your vet.

It is sometimes difficult to diagnose the cause of the diarrhea. Multiple tests may be needed.

Infectious causes (parasites, bacteria, and viruses) can be tested for via fecal flotation or fecal PCR.

Blood and urine tests will detect liver, kidney, and thyroid disease.

IBD, pancreatitis, cancer and food allergy do not show reliably on blood tests. An ultrasound can show if the pancreas and intestines are abnormal but biopsies are need to be certain of the cause of them not looking normal (infection vs. cancer vs. other reasons). Not all pathologists (the specialists your vet will send the biopsies to for evaluation) are great with the feline intestine. They can have trouble distinguishing between inflammatory, cancer, and infection.

Treatment for diarrhea can include deworming medication, antibiotics, probiotic, highly digestible diet, novel protein diet, Vitamin B injections, and immune system modifiers (these are for IBD or cancer … most commonly used is Prednisolone but others are Budesonide and Atopica - aka cyclosporine).

IBD is not cured but controlled with treatment. Relapses are likely to happen. Pancreatitis can also reoccur. If your cat goes outside parasites can happen over and over again.

So, if soft poop happens, talk to your vet.