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.

Colitis in Cats: Our Vet Explains Signs, Diagnosis & Treatment

Share

A cat having a check up at a small animal vet clinic

Taking care of a cat experiencing gastrointestinal symptoms can be quite an ordeal and cause a significant amount of stress for both you and your cat. A gastrointestinal sign that may impact your cat and make them feel ill is colitis. But what exactly is colitis, and what are some of the signs you need to look out for? Continue reading to learn more about the possible causes of colitis and how your vet will likely address the issue.

divider 1 paws

What Is Colitis?

Colitis is simply the inflammation of the colon. When this occurs, “large bowel diarrhea” may occur. This term is used to reference soft stool often associated with an increased urgency to defecate. When inflammation or infection changes the intestinal lining of the large intestines, water absorption is unable to occur effectively, which is what leads to urgent bowel movements.

What Are the Signs of Colitis?

  • Increased urgency to defecate
  • Blood in stool
  • Mucus in stool
  • Accidents in the house
  • Small amounts and increased frequency of diarrhea
  • Straining to defecate
  • Vomiting

Causes of Colitis in Cats

Cats can develop colitis due to several underlying causes. A few common causes of colitis in cats include food allergies, infection, stress, and dietary indiscretion 1.

Dietary Indiscretion

Dietary indiscretion is the consumption of food or items outside of the pet’s normal repertoire. This can cause an upset stomach and large bowel diarrhea. This type of colitis is generally acute and has the potential to resolve quickly with appropriate care.

sick cat vomiting the food on a white background
Image Credit: Tom Wang, Shutterstock

Infections

There are several types of gastrointestinal parasites, and parasitism must be considered for any cat experiencing colitis. Parasites that can cause colitis include whipworms and giardia. Often, cats will be treated with a broad-spectrum antiparasitic drug. A colitis-causing protozoan parasite that impacts young cats called Tritrichomonas foetus does not respond to typical parasitic treatments. The prognosis for cats with Tritrichomonas foetus is good and diarrhea may even resolve without intervention.

Viral and bacterial pathogens can also lead to colitis. It is important to know the FELV (Feline Leukemia Virus) and FIV (Feline Immunodeficiency Virus) status of any cat with ongoing diarrhea.

Inflammatory Bowel Disease/Food Allergies

Inflammatory bowel disease (IBD) is a syndrome in which the gastrointestinal tract creates an inflammatory response to a specific stimulus. There are several different causes of IBD, including food allergies and infections, which can result in colitis. IBD results in thickening of portions of the gastrointestinal tract which prevents normal nutrient absorption from occurring. This can lead to weight loss and a ravenous appetite.

Image Credit: Oporty786, Shutterstock

Stress Colitis

Animals under stress, whether from boarding, travel, or another source, may develop colitis. Stress colitis can quickly improve with dietary support and time. Modalities that have been proven to reduce stress, like pheromones and certain probiotics, may be helpful in these patients.

divider 3 paws

Diagnosing Colitis in Cats

If your companion is experiencing recurrent or persistent signs of colitis, veterinary care should be sought. Your veterinarian will listen closely to your cat’s history and clinical signs prior to recommending diagnostics. In most cases, a fecal sample will be evaluated. Blood work, including a CBC and chemistry, should be evaluated to identify other possible abnormalities. Colitis itself is not a diagnosis but a sign of another condition. Successful treatment of colitis is dependent on diagnosing the primary cause.

sick-stray-senior-cat
Image Credit: RJ22, Shutterstock

1. Fecal Floatation

The fecal floatation test is a common test done to screen for different types of gastrointestinal parasites. This test can be done in a hospital or at a reference laboratory.


2. PCR Test

A PCR test can be done at an outsourcing lab that tests for common gastrointestinal pathogens, including viruses. This test can provide a diagnosis through the recognition of pathogen DNA.

Siamese-elder-cat-sick-with-cancer-has-a-feeding-food-tube-attached-to-its-nose-to-stomach
Image Credit: SUJITRA CHAOWDEE, Shutterstock

3. Feeding Trials

Unfortunately, some cats may have food allergies or sensitivities. Your veterinarian may recommend a feeding trial on a particular diet. If your companion improves while on a special diet, this may be supportive of a food allergy or sensitivity.


4. Biopsy

If less invasive diagnostic avenues are pursued but improvements are not made, it may be time to discuss an intestinal biopsy. An intestinal biopsy allows the layers of the intestines to be closely evaluated and abnormalities identified.

vet holding sick cat
Image Credit: megaflopp, Shutterstock

5. Treating Colitis

The successful treatment of colitis is dependent on the underlying cause. Antibiotics may be necessary for certain bacterial pathogens, whereas antiparasitic would be indicated in the event of a parasitic infection.

If the colitis is acute and not severe, it is possible that supportive care may be initiated at first. This may require a bland diet for several days, and if concurrent dehydration is present, fluid therapy may be needed.

For cats with suspected food allergies or inflammatory bowel disease, a hydrolyzed or novel protein diet may be necessary. Some of these patients may require further interventions like steroids.

divider 2 cats

How to Care for a Cat With Colitis

If your cat is struggling with colitis, it is important to follow care instructions from your vet closely. Cats can be very particular with their litter boxes, so it is pertinent that good care is taken to ensure the litter box remains clean. Encourage hydration through the consumption of fluids, whether from canned food or water consumption.

Continue to closely monitor your cat for signs of improvement or regression. Seek veterinary help if your companion is not improving as anticipated.

vet checking a cat at home
Image Credit: Zhuravlev Andrey, Shutterstock

divider 3 paws

Frequently Asked Questions

My cat has been experiencing colitis and has been placed on a special diet. How long do I need to keep feeding the special diet?

It depends on what the diet is being used to treat. If the signs of colitis have been very acute and associated with stress or dietary indiscretion, a bland diet may have been prescribed for the short term.

Alternatively, if there is suspicion that your cat has IBD or food sensitivities, your veterinarian may want to try your cat on a hydrolyzed or novel protein diet for several weeks. If this diet works well, your cat may benefit from permanently staying on this diet.

cat on the table being checked by a vet
Image Credit: brodtcast, Shutterstock

What is the overall prognosis for colitis?

The overall prognosis is dependent on the underlying cause of colitis. Fortunately, several causes of colitis can be easily treated under the care of your veterinarian.

divider 1 paws

Conclusion

Caring for a cat with colitis can be challenging and frustrating, as there are often messes occurring outside of the litter box. There are several causes of colitis, and not all forms of colitis are treated the same. Your veterinarian can help guide you toward the best diagnostics and treatment options based on your pet’s physical examination and history.

The prognosis of colitis is good when the cause is correctly identified, although some causes of colitis may result in intermittent reoccurrences.


Featured Image Credit: Tyler Olson, 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.


Catster's Digital Magazine is Back!

Vet-approved health & behavior advice

Real cat stories & community features

When a Cat Becomes a Water Fountain – Why Cats Vomit After Drinking

Seeing a cat drink water and then promptly bring it back up can be confusing. Sometimes the explanation is fairly simple, particularly if...

Chatting About Sleeping Positions, Loafing & Cats in Tubes | Chatty Cattys, Episode 33

In this episode of Catster’s Chatty Cattys podcast, Dr. Karyn and Nicole dive deep into the fascinating world of feline sleep behaviors. From...

The Bite Stuff: The Truth Behind a Cat’s Sudden Nip

A cat bite that seems to come out of nowhere is one of the more confusing things a cat owner deals with. Everything...

Your Cat’s Purr Proves They’re One of a Kind

There are few sounds more comforting to a cat parent than the familiar rumble of a purring cat. You probably know your own...

More related

17 Friendliest Cat Breeds (With Info & Pictures)

We’ve all heard horror stories of people who bring cats into their homes that simply want nothing to do with them. You try...

Can Cats Eat Dates? Vet-Verified Nutrition Info & Facts

Can cats eat dates? The answer is not that simple. Although dates are not toxic for cats, meaning they can eat them, there...

Can Cats Eat Celery? Vet-Reviewed Nutrition Facts & FAQ

Celery is a popular chips-and-dip accompaniment, and while your cat definitely shouldn’t have the chips or the dip, what about the celery itself?...

Catster’s Weekly Photo Contest Winners: Silly Stretch (August 31, 2026)

Every week our team gets the privilege of sorting through our readers photos to choose what cats will win this weeks contest! See...

Keep reading

Can I Feed My Cat Different Brands Of Food? Vet Approved Advice

As humans, we can’t imagine eating the same food over and over again, so when it comes to our cats, is variety really the spice of life, or will our furry friends fare better on the same diet for their...

woman giving food to her cute domestic cat at home

Cat Ear Mites vs Earwax: Vet-Reviewed Ways to Tell the Difference

Earwax is entirely normal. Ear mites, on the other hand—not so much. If your cat has ear mites, they will require veterinary care. While ear mites aren’t often serious, they can cause extreme itching, discomfort, and even skin lesions if...

cat ear mites vs cat earwax featured image

10 Best Dry Kitten Foods (2026) – Reviews & Top Picks

Growing kittens need the right mix of nutrients, minerals, and vitamins to thrive, and the dry food you choose to feed these developing felines is an important choice. This stage of growth and development will set the stage for the...

two kittens eating cat food_shutterstock_MaraZe

Are String of Hearts Toxic to Cats? Vet-Reviewed Houseplants Examined

If you’re looking to add houseplants to your home, the potential options can be overwhelming. However, if your home already has a cat in residence, your choices will be limited by one important factor: whether or not the plant is...

Catster_Are String of Hearts Toxic to Cats

Cat Peeing on Dog Bed? 4 Reasons Why & How to Stop It!

When you first realize that your cat has peed on your dog’s bed, your first thought may be anger, followed by confusion. Do they not like the dog? To make matters worse, cat urine is tough to remove. It’ll take...

cat sitting near wet spot on bed

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

How Old is My Cat? Vet-Approved Ways to Determine Age

Adopting a rescue cat is one of the best feelings in the world. You get to give a cuddly feline a good home and all the love, food, play, and nap time that they want. There is always going to...

scottish fold and siamese cats sitting next to each other

Why Does My Cat Sleep on My Head? 5 Vet-Reviewed Reasons

Cats have all sorts of odd (and sometimes annoying behaviors), which sometimes include sleeping on people’s heads. Though most pet owners don’t seem to find this behavior, others find it difficult to understand why their cat is choosing to sleep...

woman-sleeping-with-her-cat

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.