Julia Ogden

Written by Julia Ogden

Updated: May 23, 2024

Why does my cat have diarrhea?

Updated: May 23, 2024

As is the case with humans, diarrhea can be the symptom of a wide range of illnesses in your cat. Some of these are temporary in nature, like an upset stomach, an infection or gut parasites. There’s also a strong link between your cat’s diet and diarrhea, so if you’ve recently swapped to a different type of food or treats, this might be a shock to their system — at the same time, who knows what unhealthy things they’ve been feasting on out in the garden away from your watchful gaze?

Sure, it’s not the most glamorous part of sharing a life with a cat, but the good news is a bout of diarrhea is normally as quick to eradicate as it is to appear in the first place.

What should I be looking out for?

If your cat has a litter tray inside, it should be obvious when they’re suffering from this particular ailment. Essentially, they’ll be going to the toilet more often and their stool will be loose or even watery. Cats that like to roam outside also bear telltale signs. If they’ve got a gurgling stomach, excessive flatulence, and a smelly bottom they’re cleaning more than they normally do, diarrhea might be the reason.

What causes diarrhea in cats?

A change in diet

If you’ve ever seen your cat tuck into something they’ve found — or caught — in the garden, you would feel safe assuming their digestive system is pretty hardy. Wrong. Even just switching over cat food can upset their insides, which is why it’s recommended to make the changeover to a new brand or recipe last a couple of weeks, slowly incorporating slightly larger quantities each time so their stomach can get used to it.

Stress and anxiety

In some instances, it might be stress and anxiety playing havoc on your cat’s guts, especially if you also notice other symptoms such as over-obsessive grooming, excessive meowing and uncharacteristically aggressive behavior. It’s worth casting your mind over any recent changes to your living environment — maybe a change in routine or a new addition to the household — so you can get to the root of the problem.

Food intolerance or allergies

Some cats can develop sensitivities or allergies to certain ingredients in their food, such as proteins or grains. This can lead to diarrhea as a result of the immune system’s response to the offending ingredient.

Ingestion of inappropriate or spoiled food

If a cat consumes spoiled or contaminated food, it can lead to an upset stomach and diarrhea. Additionally, ingesting non-food items, such as plants or foreign objects, can also cause diarrhea.


Internal parasites, such as roundworms, hookworms, or giardia, can cause diarrhea in cats. These parasites may be acquired through exposure to contaminated environments, infected prey, or from their mother during nursing.


Bacterial, viral, or protozoal infections can cause diarrhea in cats. Common culprits include Salmonella, Campylobacter, or feline panleukopenia virus. These infections may occur due to exposure to contaminated environments or contact with infected animals.

Underlying conditions

Diarrhea can be a symptom of underlying medical conditions in cats, including inflammatory bowel disease, pancreatitis, kidney disease, liver disease, hyperthyroidism, or certain types of cancer. These conditions may require veterinary evaluation and treatment.

What should I do if my cat has diarrhea?

In mild cases lasting less than a day, diarrhea is certainly unpleasant for your cat — not to mention your nostrils! — but largely nothing to be too worried about. Here are some things a parent can do to aid recovery.

  • Make sure your cat stays hydrated as they’re losing lots of fluids during this time.
  • If they can manage to keep a meal down, serve them some bland and inoffensive meals, such as boiled chicken or skinless, boneless white fish. 
  • They might need a bit more rest than normal, so make sure they’ve got somewhere peaceful to convalesce — preferably not too far from their litter tray.
  • You might also want to consider giving them a food designed specifically for a sensitive stomach.

Should I call the vet?

If the diarrhea lasts longer than 24 hours or is accompanied by other worrying symptoms (blood in the poo, in particular), it’s time to get the vet involved, as they will be able to work out if it’s down to a harmful virus or a chronic medical condition. 

At the same time, you should alert them immediately if you suspect your cat’s consumed something not meant for their stomachs, be that a foreign object or maybe even a poisonous item. 

Thankfully, the majority of things that bring about diarrhea in a cat can be treated and with a vet’s assistance or even just a little R&R at home, they should be back to their usual selves in no time at all.

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