What Are the Causes of Chronic Cat Diarrhea?

Chronic diarrhea in a cat can result from a number of conditions. If your cat has diarrhea, call your veterinarian. A complete work-up may reveal the cause of the diarrhea. Some cases may be more resistant to an accurate diagnosis. If the diarrhea persists, actively pursue the cause of it with your vet.

  1. Inflammatory Bowel Disease

    • Inflammatory Bowel Disease (IBD) can cause chronic bursts of vomiting and diarrhea. While the cause of IBD is unknown, it creates microscopic changes in the bowel tissue that suggest immunology factors may play a part. IBD in characterized by the infiltration of inflammatory cells into the mucous lining of the cat's bowels. No cure exists for IBD, but symptoms can be managed with diet and medication.

    Food Allergy

    • Food allergies can often cause chronic diarrhea in a cat, along with other symptoms, such as excessive scratching and dermatitis. It is difficult to determine if a cat is suffering from food allergies, but if the symptoms occur year round---thus ruling out seasonal allergies---it is a good idea to try and rule it out. Your vet may suggest food trials and elimination diets to determine if food allergy is the cause of your cat's diarrhea. This consists of feeding your cat a novel source of protein and carbohydrate for 12 weeks, such as duck and potato or venison and potato. If there is no change in symptoms, a second food trial may be suggested.

    Partial Obstruction

    • A partial obstruction or blockage can cause chronic diarrhea in a cat. The obstruction may be caused by cancer, ingestion of foreign bodies (such as a piece of string) or intussusception (the telescoping of the bowel into itself). Cats generally require surgery when there is a bowl obstruction.

    Hypothyroidism

    • Chronic diarrhea may be caused by hypothyroidism. Other symptoms may include vomiting, weight loss (despite increased appetite), depression or irritability and/or lethargy. Hypothyroidism can be diagnosed through blood work which checks the blood levels of thyroid hormone. It can be treated with surgery, which removes the malfunctioning thyroid, or with medication that controls the levels of thyroid hormone.