Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Cat Diarrhea: Causes & Care Guide (Vet Answer)

Share

A small gray and white fluffy cat getting out of a litter box.

One of the Catster editors recently asked me a few questions about poop. She wondered whether she needed to be concerned if her cat had a single runny poop. She also wondered whether pooping outside of the litter box might be a sign of a veterinary problem. Poop doesn’t exactly make the world go ’round, but it is something that, for better or for worse, is a major part of life. So, let’s talk about cat poop and cat diarrhea!

divider cats oct 2024

Cat diarrhea vs. normal cat poop

Ideally your cat produces nicely formed stools without difficulty on a daily basis. They are mostly easy to scoop out of the box, and they’re comparatively innocuous in general.

Cat diarrhea comes in varying levels of severity. Abnormally soft stools can range from incompletely formed to “soft serve” to “cow patty” to liquid to hemorrhagic. Cat diarrhea, like human diarrhea, occurs when residual undigestible portions of food pass through the intestines abnormally fast, or when excess fluid is added to the stool by the large intestines.

Cat Poop Chart
You are free to use this image, but please link back to Catster.com for credit

What causes cat diarrhea?

Practically speaking, there are a number of causes of cat diarrhea. Sometimes, cat diarrhea may be a relatively minor problem such as a mild reaction to a diet change. Mild dietary indiscretion can also cause cat diarrhea. As a child I owned a cat who was lactose-intolerant; on the few occasions I tried to create a Norman Rockwell-esque scene by offering her a saucer of milk (you should never give cow’s milk to a cat!), she created a very non-Rockwell-esque scene in the litter box.

Stress is another potential cause (cat diarrhea can occur if something literally scares the you-know-what out of them). And finally, more serious problems can cause cat diarrhea. These range from treatable issues like parasites and mild intestinal infections to more serious problems such as exposure to toxins, foreign objects in the intestines, liver or kidney disease, inflammatory bowel disease (also known as infiltrative bowel disease, or simply IBD), and cancers such as lymphoma or intestinal adenocarcinoma.

If you are concerned about the health and well-being of your pet, seek veterinary advice for the best course of action.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money

When should you worry about cat diarrhea? What if your cat has diarrhea and seems fine otherwise?

So when is cat diarrhea a big deal? When it’s really bad, when it’s accompanied by other symptoms, or when the cat feels or looks significantly sick.

For instance, if your cat has one soft stool but is still playful and eating and drinking normally, you probably don’t need to rush to the vet. This is especially true if you just switched foods (in which case you should consider switching back), or if you know she consumed a suspicious but not especially dangerous food item (such as turkey skin or milk).

However, if your cat is lethargic, won’t eat, is suffering from profuse hemorrhagic diarrhea, has 10 episodes of diarrhea in one day, or if vomiting occurs concurrently with the diarrhea, then you need to seek veterinary attention. Vomiting and diarrhea often occur together, and they are a dangerous combination because they can trigger severe dehydration.

If your cat is having frequent diarrhea, a checkup is a good idea even if she’s not showing any other symptoms. Some cat parasites can spread to people, and IBD and lymphoma are serious problems. Chronic cat diarrhea should not be ignored.

divider cats oct 2024

Cat diarrhea, cat constipation and pooping outside of the litter box

How about pooping outside of the litter box? Cat diarrhea is a common cause of this behavior, so if your cat has an abnormally soft stool outside of the box, then what you really need to focus on is the diarrhea.

Conversely, constipation also can cause cats to defecate in inappropriate places. This appears to occur because cats grow weary of going back and forth to the litter box without success, and begin trying to eliminate the contents of their bowels wherever they may be. Constipated cats may posture and strain unproductively in or out of the box, and if they produce stool it may be hard and dry.

Constipation isn’t just miserable. It’s also potentially life-threatening, and I have encountered several unfortunate cats who died from the stress of trying to defecate while hopelessly constipated. Cats with urinary obstructions can also sometimes look constipated or pass feces outside of the box while they are straining to urinate, and urinary obstruction is urgently life-threatening. Some cats with masses or tumors in their rectums or near their anuses will defecate outside of the box — often with signs of discomfort.

divider cats oct 2024

The bottom line on what to do about cat diarrhea

In short, if your cat seems to be having any distress in passing urine or feces, then book an immediate vet visit.

However, some cats intermittently (or regularly) pass normal bowel movements outside of the litter box. Most of the time this is a behavioral issue. The first step in such cases is to see the vet to be sure there is no medical problem. After getting a clean bill of health, the next step is to implement a behavioral modification plan (this link addresses urinating outside of the box, but the treatment tactics are the same). And take comfort from one fact: Finding cat poop outside of the box may be unpleasant, but it’s better than finding urine.

Read more on cat poop and cat diarrhea on Catster.com:


Featured Image Credit: Africa Studio / Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Do Cats Cause Schizophrenia? Scientists Find a Link – Here’s What It Means

Being a fierce advocate (and occasional recipient of) mental health support and awareness, the term ‘crazy’ is not one I like to fling...

One in 100 Cats Gets Diabetes – Here’s How to Catch It Early

One in every 100 cats develops diabetes.1 That’s not a rare, unlucky condition reserved for cats with obvious health problems. It’s common enough...

Dramatic Rescue Turns Into Dramatic Reunion

What started as a routine call for the RSPCA became a heroic, five-hour rescue featuring one trapped and traumatized cat, an emotional family...

Ask Dr. Paola – Help! How Do I Know if it’s Ear Mites! (May 4, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

More related

7 Pet-Friendly Hotels in Gulf Shores, AL (2026 Update)

If you’re planning a trip but don’t want to leave your dog or cat behind, you’ll need to find a pet-friendly hotel in...

Catit Cabrio Carrier 2026 Review: Pros, Cons & Verdict

Review Summary Is your cat a homebody who hates traveling in cramped, dark crates? Who could blame them? That’s why Catit came up...

CoyoteVest Pet Body Armor Review 2026: A Detailed Look

If you have an adventurous cat, you probably worry about them more than you would like. CoyoteVest is a company that started to...

Can Cats Eat Blueberries? Our Vet Answers!

There are many debates when it comes to what foods cats can and cannot eat. Some people believe that cats can eat any...

Keep reading

Why Healthy Cats Still Vomit Sometimes (And How to Respond)

A cat that just vomited needs a specific kind of care, and the feeding decisions you make in the next few hours actually matter. Too much too soon can make things worse. Nothing at all for too long isn’t great...

sick cat lying on the sofa

10 Senior Cat Health Problems: Vet-Verified Common Issues

Like people and other animals, cats start to show signs of aging as they reach their senior years. Typically, 10 years is considered to be senior for a cat, although many do go on to live to 17 or 18...

Catster_Health Problems of Senior Cat

Why Does My Cat Open Drawers? 8 Vet-Reviewed Tips to Stop Them

Cats can be a complete joy to own, but sometimes their inquisitive personalities can get them into trouble. This is often the case when they start getting into every drawer in your home, and while it can be cute at...

cat trying to open a drawer

Are Cats Self-Aware? Do They Understand Mirrors & Their Self-Reflection? (Vet-Reviewed)

Self-awareness in animals is often seen as a sign of intelligence, and it is something that scientists have looked at for decades, not only in cats but also in virtually every species of animal. Despite what it might look like...

cat burp_Dimitris Vetsikas_Pixabay

How to Give a Cat Liquid Medicine: 8 Vet-Approved Tips

Your furry friend being sick makes you feel horrible, especially when there isn’t much you can do to make them feel better. It’s a bad experience for you and your cat, and when you have to give the cat liquid...

infusion of liquid medicine by a veterinarian

Can Cats Get Lyme Disease? Vet Approved Facts, Treatment & Prevention Tips

Owning a cat, especially one that enjoys roaming outdoors, comes with the concern of seasonal ticks. As a human, finding a tick firmly attached to your skin is concerning, and it evokes immediate worry about tick bite fever and Lyme...

removed tick from cat

Spay/Neuter Complications in Cats: What Vets Want You to Know

Your cat’s spay appointment is booked. You’ve arranged time off work, prepped a quiet recovery space, and bought one of those cone collars they’ll definitely hate. You know this surgery is the right call—it prevents unwanted litters, cuts down on...

vet checking a cat's stomach

Is Free Feeding Cats the Best Method? Vet-Verified Pros & Cons

How and when you feed your cat is almost as important as what you feed them. Indeed, your cat relies on you to determine when, what, and how they eat, which impacts their well-being and health on many levels. For...

cat eating food from the bowl

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.