Diarrhea in Cats

What is diarrhea?

Diarrhea is unformed or loose stools that occur in larger amounts or more often than usual. Diarrhea is not a disease, but rather a sign of many different diseases.

Diarrhea associated with minor conditions can often be resolved quickly with simple treatments. Diarrhea may also be the result of serious or life-threatening illnesses, such as organ system failure or cancer. Even diarrhea caused by mild illnesses may become serious if treatment is not begun early enough.

How can I tell if my cat has diarrhea?

If your normally well-trained cat suddenly starts having accidents around the house and the stools are unformed or fluid, then diarrhea is obvious. However, if the cat is still using the litter box and covering up its feces or if it defecates outdoors, you may not initially notice diarrhea. In long-haired breeds, you may notice staining or soiling of the fur around the back end.

It is important to remember that some variation in the consistency of stools occurs in healthy cats. If frequent liquid or semi-liquid stools persist for more than two days, you should consult your veterinarian. If you have more than one cat, you will need to determine which one has diarrhea or if it is occurring in multiple cats.

What causes diarrhea?

Diarrhea is the result of faster movement of fecal material through the intestines, combined with decreased absorption of water, nutrients, and electrolytes. Common causes of diarrhea in cats include:

• Infection with bacteria, viruses, coccidia, or parasites such as worms (hookworms, roundworms)
• Non-infectious irritants, such as chemical toxins or poisonous plants
• Changes in diet or food intolerances

Diarrhea can also be a sign of a more serious underlying disorder such as food allergies, severe bacterial or viral infections (such as panleukopenia), inflammatory bowel disease, organ dysfunction, cancer, or other systemic illnesses.

How serious is diarrhea in cats?

The seriousness of diarrhea depends on how long it persists and how many other clinical signs accompany it. If your cat has severe, bloody diarrhea or shows more generalized signs of illness, the cause may be serious and you should seek medical attention as soon as possible. Generalized signs of illness may include:

• Weakness
• Fever
• Vomiting
• Abdominal pain
• Dehydration
• Loss of appetite
• Weight loss

How is the cause of diarrhea diagnosed?

Your veterinarian will diagnose the cause of diarrhea by reviewing your cat’s medical history, performing a physical examination, and in some cases, taking samples for laboratory testing. The nature of the diarrhea, such as its color, consistency, smell, and frequency, is important in determining the cause.

Your veterinarian will likely request a sample of fresh fecal material to be brought to your appointment. You may also be asked a series of questions about your pet's diarrhea, such as when the diarrhea started, how often it occurs, what it looks like, and any recent changes in your pet's diet or environment.

In mild cases of diarrhea, your veterinarian may not perform further diagnostic testing unless initial treatment fails or the condition worsens. Additional tests may include bloodwork, stool and rectal swab samples for parasite examination, DNA testing for infectious organisms, bacterial culture, radiographs (X-rays), ultrasound, and endoscopic exam.

How is diarrhea treated?

For otherwise healthy adult cats, your veterinarian may advise you to withhold food for a short time or to feed small amounts of a veterinary diet for gastrointestinal problems. These diets are specifically formulated with a balance of fibers that feed the good bacteria in your cat’s intestine and certain antioxidants that support your cat’s immune system. It is important to always provide easy access to water, because a cat with diarrhea can quickly become dehydrated.

Medications and supplements may be prescribed, such as anti-diarrheal agents, de-wormers, and probiotics (bacteria that support intestinal health). There are several probiotic products that may help cats with diarrhea. However, consult your veterinarian before offering anything to your cat, as the quality and effectiveness of these products are not always known.

Many cases of acute (sudden) diarrhea respond well to this conservative treatment, allowing the body's healing mechanisms to correct the problem, without the initial cause ever being established. As the stools return to normal, you can usually transition back to your cat’s regular diet over seven to ten days.

If your cat does not improve within two days, your veterinarian may recommend further testing or more aggressive treatment. Severe or prolonged diarrhea can result in significant dehydration and other problems caused by fluid loss, and your pet may require hospitalization for intravenous fluid therapy or other, more intensive, treatments.

What is the prognosis?

The prognosis depends on the severity of the diarrhea, the specific diagnosis, and your cat’s response to treatment. Most cats with simple diarrhea will make a full recovery, while cats with chronic diarrhea may require long-term dietary management or medications to keep the condition under control.