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Chronic Diarrhea in Cats

Chronic Diarrhea in Cats

Chronic diarrhea is defined as diarrhea that lasts for three weeks or longer. At times, your cat’s fecal material can have fresh blood or mucus in it. There could be some kind of intestinal disease present, especially if your cat has experienced a change in appetite and has lost weight, shows a diminished body condition, has developed a poor hair coat and is less active. It’s important that you check in with your veterinarian as soon as possible.


There are a number of conditions or diseases that can lead to chronic diarrhea. These include viruses, certain bacteria, intestinal parasites, some protozoa, fungal infections, food intolerances or allergies, certain medications and toxins, liver disease, pancreatic disease, kidney disease and an overactive thyroid, for example. In addition, when your cat does not properly absorb nutrients she could lose weight and have changes in her bowel movements. In this situation you should seek the advice of your doctor.


  • Loose, watery stools that continue for three weeks and longer
  • Color change in the stool
  • Blood and/or mucus in the stool
  • Increased number of stools
  • Increase in the volume of stool produced
  • Difficult or painful eliminating
  • Loss of appetite
  • Weight loss
  • Poor hair coat
  • Lethargy or sluggishness


First, your veterinarian will review a complete medical history, perform a thorough physical examination and conduct tests to help diagnose the primary cause of your cat’s chronic diarrhea. Which tests your doctor may do will be based on your individual cat’s history and physical examination findings and may include:

  • Fecal examination for parasites
  • Complete blood count (CBC)
  • Chemical profile
  • Urinalysis
  • Abdominal x-rays
  • Chest x-rays
  • Tests for absorption and digestion problems
  • Analysis for viral diseases
  • Abdominal ultrasound
  • Upper GI barium series
  • Barium enema (if there’s a question of colon disease)
  • Endoscopic examination and biopsy of the stomach, small intestine, and colon with a pathologist review and cultures for bacterial and fungal organisms
  • Serum bile acids testing
  • A blood lead level test

If test results don’t reveal anything, your veterinarian may find exploratory abdominal surgery to be helpful in making a diagnosis.


Your veterinarian will attempt to come to a final diagnosis before initiating any treatment because each disease process that can cause chronic diarrhea will have a different treatment associated with it. Some of the most common treatments that your veterinarian may prescribe are:

  • Deworming (for intestinal parasites)
  • Short course of antimicrobial drugs (for intestinal parasites and protozoans)
  • Other antibiotics are sometimes required
  • Incorporating a high-fiber diet or hypoallergenic diet depending on symptoms
  • If hospitalized, intravenous fluids, supplemental nutrition and vitamins and intestinal protectants may be needed.
  • Some chronic diarrheal diseases cannot be cured and require life –long care to manage

At Home

It’s critical that you pay close attention to your cat’s chronic diarrhea. Keep tabs on her stool volume and its consistency, how often she eliminates and any difficulty in defecating. Note if blood or mucus is in the stool. You should track your cat's weight, appetite and activity level. Any medications your veterinarian prescribes should be given exactly as directed.