Diarrhea in cats happens when stool becomes loose or watery, and it can occur for many different reasons. Understanding what might cause diarrhea is an important part of caring for your cat's health. Some causes are minor and resolve on their own, while others may need veterinary attention.
Learn How to Make Apple Juice at Home →
One of the most common causes of cat diarrhea is a sudden change in diet. Cats have sensitive digestive systems, and switching food too quickly can upset their stomach. If you're changing your cat's food, veterinarians typically recommend doing this gradually over 7 to 10 days, mixing increasing amounts of the new food with the old food. This slow transition gives your cat's digestive system time to adjust.
Food sensitivities and allergies also cause diarrhea in cats. Some cats don't tolerate certain ingredients well, such as dairy, fish, or certain grains. Unlike humans, most adult cats are actually lactose intolerant because they lose the ability to digest milk after they stop nursing. If your cat has recurring diarrhea, a food sensitivity might be the culprit.
Stress and anxiety can trigger digestive upset in cats. Changes in the household—such as moving, new pets, or changes in routine—can cause stress-related diarrhea. This type typically improves once your cat adjusts to the change and feels more secure in their environment.
Intestinal parasites are another common cause, especially in younger cats or outdoor cats. Common parasites include roundworms, hookworms, and giardia. These parasites are more than just uncomfortable; they can affect your cat's nutrition and overall health. A veterinarian can identify parasites through stool testing.
Bacterial or viral infections can also cause diarrhea. Viruses like feline panleukopenia and feline coronavirus can lead to digestive problems, along with other symptoms. Bacterial infections from organisms like Salmonella or E. coli may cause diarrhea as well.
Practical takeaway: Keep a simple log of when your cat has diarrhea, what they ate, and any other changes in your household. This information helps you spot patterns and gives your veterinarian useful details about what might be causing the problem.
Some cats experience chronic diarrhea caused by underlying medical conditions that require ongoing management. Recognizing these conditions helps you understand why your cat has persistent digestive issues and what treatment options might help.
The Tap House Chattanooga Craft Beer Guide →
Inflammatory bowel disease (IBD) is one of the most common causes of chronic diarrhea in cats. With IBD, the intestinal lining becomes inflamed, making it difficult for the body to digest food properly and absorb nutrients. Cats with IBD may also lose weight, have poor appetite, or experience vomiting. The exact cause of IBD isn't completely understood, but it may involve an abnormal immune response or food sensitivity. Managing IBD typically involves dietary changes, and sometimes medication.
Hyperthyroidism occurs when the thyroid gland produces too much hormone, speeding up the cat's metabolism. This condition is common in older cats—studies show it affects about 2 percent of the cat population overall, but rates are much higher in senior cats. Symptoms include increased appetite, weight loss, and diarrhea. The good news is that hyperthyroidism can be diagnosed with a blood test and managed through medication, dietary changes, or other treatments.
Pancreatitis, or inflammation of the pancreas, can cause diarrhea along with vomiting, loss of appetite, and abdominal pain. Cats with pancreatitis may act uncomfortable or "hunched." This condition needs veterinary diagnosis and treatment, and in some cases may be related to other diseases or medications.
Intestinal cancer, while less common than other conditions, can develop in cats and cause persistent diarrhea. Older cats and cats with certain risk factors are at higher risk. Early detection makes treatment more effective.
Kidney disease and liver disease can also show up as diarrhea, along with other symptoms like increased thirst or changes in appetite. These conditions are especially important to identify early so that treatment can begin promptly.
Practical takeaway: If your cat has had diarrhea for more than a few days, or if it keeps returning, schedule a veterinary visit. Your veterinarian can run tests to identify or rule out underlying conditions and recommend the right treatment plan.
Many cases of mild, short-term diarrhea can be managed at home while you monitor your cat. Home care focuses on keeping your cat comfortable and hydrated while you watch for signs of improvement or worsening.
Learn About Removing Microsoft Edge From Your Computer →
Hydration is the most important thing to focus on when your cat has diarrhea. Diarrhea causes fluid loss, which can lead to dehydration, especially in kittens and older cats. Make sure your cat has access to fresh water at all times. Some cats drink more if you provide running water from a fountain. You can also offer wet food, which has higher water content than dry food. Watch for signs of dehydration like dry gums, excessive thirst, or lethargy.
If your cat hasn't eaten in more than 24 hours, or if you want to give their digestive system a rest, a brief fasting period may help. Some veterinarians recommend fasting for 12 to 24 hours followed by a bland diet. However, don't fast kittens, senior cats, or cats with other health conditions without veterinary guidance.
Bland diets can help settle an upset stomach. Boiled chicken (without seasoning or bones) mixed with plain white rice is a common home remedy. You can also try plain, cooked turkey or canned pumpkin puree (not pumpkin pie filling, which contains sugar). Some cats respond well to over-the-counter digestive care cat foods that are formulated to be easier to digest. Introduce any new food gradually, mixing it with regular food over several days.
Probiotics—beneficial bacteria that support digestive health—may help some cats. Probiotics designed specifically for cats can be added to food. While research shows mixed results, some cats do seem to improve with probiotic supplementation. Always choose products made for cats, as human probiotics aren't appropriate for feline digestive systems.
Pumpkin puree has been used traditionally for digestive upset in both diarrhea and constipation. The fiber content may help firm up stool. A small amount—about 1 to 4 teaspoons per day mixed into food—is typical. Use plain canned pumpkin, not the spiced pie filling.
Keep the litter box clean and accessible. Diarrhea-related messes are normal, and a clean litter area reduces stress and helps prevent bacterial overgrowth. Multiple litter boxes are ideal—the general guideline is one box per cat plus one extra.
Practical takeaway: Create a simple health log for your cat. Note the appearance and frequency of diarrhea, appetite level, water intake, and energy level. This helps you track whether your cat is improving or declining, and provides valuable information for your veterinarian.
Long-term management of diarrhea often involves choosing the right food for your cat's digestive system. Since many cases of chronic diarrhea relate to food sensitivities or digestive sensitivity, diet plays a major role in keeping your cat comfortable.
Build Your Own Doghouse Step By Step Guide →
Limited ingredient diets contain fewer components, which makes it easier to identify if a specific ingredient is causing the problem. These diets typically have a single protein source and minimal additives. Common limited ingredient options include foods with fish, chicken, or turkey as the only protein. If your cat has diarrhea when eating a multi-protein diet, switching to a single-protein option may help resolve the issue.
Novel protein diets use protein sources that your cat hasn't eaten before, such as venison, duck, or rabbit. These can be helpful if your cat has developed sensitivities to common proteins like chicken or fish. The theory is that if your cat's immune system hasn't been exposed to these proteins, there's less chance of a reaction.
Prescription
This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.