cat diarrhea - causes, symptoms and treatments

Cat Diarrhea: Causes, Symptoms & Treatments

Diarrhea is one of the most common ailments among pets. The condition is characterized by loose or liquid bowel movements, which happen more frequently than usual. Your feline friend might experience a bout of diarrhea for a variety of reasons. Often, with a little time and rest, your cat will be feeling like their old selves in a day or so, but other cases can be more serious, so it’s important to keep a close eye on them.

Below we take a look at how to spot a case of diarrhea that might need veterinary attention, some of its most common causes, and how your cat might be treated, both at the vet’s and at home.

cat diarrhea

Causes of Diarrhoea in Cats

Diarrhea can be triggered by a whole host of causes, both benign and more serious. Here are some of the most common:

  • Dietary Change

Just like humans, a sudden change in diet can give cats an upset stomach. If you have recently changed cat food brands, switched from a wet to dry diet (or vice versa), or added new supplements to your cat’s diet, they might experience a bout of diarrhoea. In cases such as these, your pet will usually be back to normal in a few days, but do be sure to keep a close eye on them.

  • Eating Spoiled Food

Another common cause of digestive issues in cats is the consumption of moldy food. If your cat has raided the trash, for example, they might have ingested an expired product, which could trigger vomiting, diarrhea, or both.

  • Food Intolerance

Humans aren’t the only animals who can have food allergies. Cats can also be allergic to ingredients such as soy, wheat, or dairy. If your cat is suffering from a food allergy, their digestive distress is likely to be accompanied by symptoms such as sneezing or coughing, scratching, and swelling – particularly of the paws and throat. If you suspect your cat has a food allergy, consult your vet as soon as possible. The longer your pet is exposed to the allergen, the worse their symptoms can become.

Related Post: Best Hypoallergenic Cat Food

  • Infection

Both bacterial and viral infections can also cause diarrhea in your cat. If they suddenly experience diarrhea, it could be the result of the flu or stomach bug. These pathogens can weaken the digestive system, meaning foods are not broken down as usual. This can result in loose or watery stool. Diarrhea associated with a cold or flu will usually clear up within a few days, but if your cat contracts a bacterial infection of part of their digestive tract, your vet might need to prescribe antibiotics.

  • Parasites

Certain internal parasites, including coccidia, Giardia, and roundworm, can induce diarrhea in cats. Your vet will be able to identify parasites through a fecal smear test, to rule out other causes. Diarrhea triggered by internal parasites is likely to be accompanied by symptoms including loss of appetite, bloody stool, or a swollen stomach.

  • Inflammatory Bowel Disease

Inflammatory Bowel Disease (IBD) causes a cat’s intestines to swell. The condition has no single known cause, but experts suspect that food allergies and extreme sensitivity to bacteria are usually behind the issue. When a cat suffers from IBD, diarrhea might be accompanied by symptoms including weight loss, tiredness, abdominal pain, and flatulence. If you suspect your cat is suffering from IBD, it’s best to consult with your vet as soon as possible, and possibly include some ibd cat foods in your pet’s diet.

  • Liver Disease

Diarrhea can also be a symptom of liver disease. This occurs when a cat’s liver is overwhelmed by fat, which happens most frequently when they do not eat for extended periods of time. Other symptoms of liver disease include lethargy, weight loss, a change in appetite, and vomiting.

  • Kidney Disease

Kidney disease is most common in older cats. Damage to the kidneys can be the result of multiple causes, from cancer to infection. Symptoms include diarrhea, excessive thirst, reduced appetite, and bad breath. Unfortunately, kidney disease does not have a cure, but symptoms can be treated to extend your cat’s life and improve its quality. Like all animals, cats’ organs begin to deteriorate with age, kidneys are often the first to show signs of this deterioration.

Related Post: Best Cat Food for Kidney Disease

  • Tumors in the Digestive Tract

Tumors along a cat’s digestive tract can interfere with the digestive process, which often results in diarrhea. These tumors may or may not be cancerous, and a biopsy carried out by your vet will reveal this. If your cat is suffering from a tumor in their digestive tract, they will likely experience weight loss and discoloration of stool alongside diarrhea. You may also be able to feel a hard lump in their stomach or abdomen.

  • Medication

Diarrhea can also be a side effect of certain medications. Common culprits include antibiotics and cancer-fighting drugs. For short courses of drugs, simply keeping an eye on your cat and ensuring they have access to plenty of water should be enough, but if they need to be on the medication long-term, you should probably consult your vet. They may be able to prescribe an alternative medication or additional treatment to reduce diarrhea.

  • Hyperthyroidism

Hyperthyroidism occurs when the thyroid gland produces more hormones than usual. This is the result of an enlarged thyroid, often caused by a non-cancerous tumor. As well as diarrhea, symptoms of hyperthyroidism include weight loss, an unkempt coat, and increased water consumption and urination.

  • Colitis

Colitis is an inflammation of the large intestine or colon. It can be attributed to a wide variety of causes, including stress and infection. Cats suffering from colitis might exhibit symptoms including lethargy, weight loss, and diarrhea. The treatment of colitis will depend upon its exact cause, but will often include the administration of a high fiber diet and anti-inflammatory medication.

cat sick with diarrhea

Other Symptoms to Watch Out For

Diarrhea is extremely common in both pets and their owners. In itself, the condition is more inconvenient than dangerous, but it can trigger other, more serious problems, and be accompanied by more severe symptoms. Below are some additional symptoms and issues to watch out for when your cat has diarrhea.

  • Dehydration

The most common complication associated with diarrhea is dehydration. Dehydrated cats will generally exhibit lethargy, dry gums, a refusal to eat, and sunken eyes. You can also check your cat for dehydration with the skin pinch test. Gently pinch a small section of their skin between your thumb are forefinger; in healthy cats, the skin will immediately spring back to its original position. If your cat is dehydrated, the skin will fall back into place much more slowly. It’s a good idea to carry out the skin pinch test when your cat is healthy for reference.

  • Blood in Stool

If your cat’s diarrhea also contains blood, this could be a sign of an underlying issue. Blood in the stool suggests internal bleeding, which can be caused by parasites, irritation in the digestive tracts, tumors, or other health issues. If you find blood in your cat’s stool under any circumstances, speak to your vet.

  • Changes in Appetite

If your cat’s diarrhea is accompanied by an increased or suppressed appetite, this could reveal the underlying issues behind it. Certain parasites can cause an increased appetite, since they hijack some of the nutrients ingested by the cat, for instance. If your cat goes off their food, several causes could be at play, and you should consult a veterinary professional as soon as possible.

  • Fatigue

If your cat’s diarrhea is accompanied by a general lack of energy, this suggests that a more urgent underlying cause is present. If your cat experiences digestive issues, keep an eye on how your cat acts, noting any changes to their normal behavior.

  • Signs of Pain

If your cat appears to be in pain, particularly when defecating, you should take them to the vet as soon as possible. Signs of pain might include meowing constantly, crying, or excessive grooming.

When to Contact Your Vet

Generally speaking, you should consult your vet if:

  • Your cat’s diarrhea lasts for more than two days
  • The diarrhea is accompanied by fever
  • You notice your cat exhibiting symptoms of pain
  • You notice a change in behavior such as lethargy
  • Your cat’s appetite changes
  • Your cat is vomiting
  • Your cat appears feverish

These symptoms suggest that the root of the diarrhea is something more serious than the stomach flu or change in diet, and you should seek advice from a veterinary professional as soon as possible.

What Your Vet Will Do

Usually, when you take your cat to the vet because of diarrhea, they will request a stool sample. Analysis of this sample will help them to ascertain the root of the issue. This sample will be tested for parasites and bacterial infection. A blood sample may also be taken, to test for other possible causes. If the vet suspects that a tumor is the cause of the digestive issues, they will most likely carry out an ultrasound scan or endoscopy. To determine whether or not a tumor is benign or malignant, a biopsy will usually be taken.

Diarrhea Treatments

How your cat’s diarrhea is treated will depend upon the cause of the issue and the severity of the symptoms.

If your vet believes that the trigger is dietary, they will recommend changing your cat’s diet. This could include introducing them to high fiber cat food, or avoiding certain ingredients if a food allergy is suspected.

In the case of a bacterial infection, antibiotics will be prescribed. Bear in mind that these drugs can sometimes cause diarrhoea themselves, so your cat may take longer to return to normal than expected.

If the stool sample reveals the presence of parasites, medication will be prescribed to clear the infection.

Diarrhea caused by more chronic conditions may need to be treated with longer courses of medication, or surgery in the case of tumors.

In all instances, your vet might suggest an anti-diarrheal medication. This will improve your cat’s comfort, and help to reduce the risk of dehydration.

Looking After a Cat with an Upset Stomach at Home

Most cases of diarrhea are nothing to worry about and will clear up in a day or so. When your cat first experiences diarrhea, there is plenty you can do to help them recover at home.

  • Ensure they stay hydrated

Dehydration can cause a whole raft of health issues and is a real risk for a cat suffering from diarrhea. Make sure your cat always has access to plenty of clean water to prevent this from happening.

Related Post: Best Cat Water Fountain

If your cat is reluctant to drink, try turning on a tap – cats prefer to drink running water, as this more closely reflects what their wild ancestors would do. To a cat’s survival instincts, still, water has the potential to be stagnant.

  • Briefly fast your Cat

Fasting your cat for 12 to 24 hours gives their digestive system a break and a chance to right itself. Be sure not to fast your cat for any longer than this, however. If cats go without food for too long, their liver is at risk of being damaged. If your cat continues to experience diarrhea following a brief fast, contact your vet.

  • Try a change of Diet

If you have recently changed your cat’s diet, try returning to their original food to see whether this resolves the issue. If your cat defecates infrequently, trying a low-fiber, easily digestible diet can help. Conversely, if your cat visits the litter box very frequently, introducing more fiber into their diet is often a good idea. If you are unsure about what kind of diet is best for your cat, your vet will be able to advise you.

Related Post: Best Cat Litter Box

  • Try Probiotics

Just like humans, cats play host to communities of beneficial bacteria in their digestive systems. Giving your pet a cat probiotic will help this good bacteria to thrive, which could resolve digestive issues.

If these home treatments do not improve your cat’s condition within a couple of days, consult your vet as soon as possible.


  1. Ian Battersby, Differential Diagnosis And Treatment Of Acute Diarrhoea In The Dog And Cat, British Veterinary Association
  2. Peters S, A Cat With Diarrhoea Associated With The Massive Presence Of Cyniclomyces Guttulatus In The Faeces, Europe PMC
  3. D.B.Murdoch, Diarrhoea In The Dog And Cat I. Acute Diarrhoea, ScienceDirect
  4. Forshell, U., Chronic Diarrhoea Caused By Tritrichomonas Foetus In The Cat, CAB International

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