Why Do Cat Have Diarrhea? Common Causes & When It's Serious

Seeing loose, watery stool in your cat’s litter box can be alarming. Diarrhea is a common feline health issue with a wide range of potential causes, from dietary changes to serious diseases.

While mild, temporary bouts are often not a major concern, chronic or severe diarrhea can lead to dehydration, malnutrition, and even be life-threatening if left untreated.

It’s important for cat owners to understand the common causes of cat diarrhea, how to manage mild cases at home, and when it’s crucial to seek veterinary care. This article provides an overview of the most frequent reasons for diarrhea in cats, tips for relieving symptoms, and advice on identifying when diarrhea becomes a medical emergency requiring prompt vet attention.

What Causes Diarrhea in Cats?

There are many possible reasons a cat might develop diarrhea. Some common causes include:

Dietary Changes or Intolerances

An abrupt change in diet can upset your cat’s digestive system. Even if your cat is not typically sensitive, abruptly switching foods or brands may cause temporary loose stool or diarrhea. Food intolerances to specific ingredients can also cause diarrhea, especially in cats with inflammatory bowel disease.

Infections

Bacterial, viral, or parasitic infections often cause diarrhea. Common offenders include salmonella, campylobacter, clostridium, panleukopenia virus, feline immunodeficiency virus (FIV), and intestinal worms or protozoa like giardia. Diarrhea caused by infection is more common in unvaccinated kittens.

Foreign Objects

Cats who swallow string, fabric, or non-food objects may experience diarrhea as the foreign body irritates the digestive tract. Foreign objects can also cause dangerous obstructions leading to straining and bloody stool.

Toxins

Ingestion of toxins like household cleaners, plants, or human medications can irritate the digestive tract. Diarrhea may occur along with drooling, vomiting, dilated pupils, tremors, or lethargy.

Dental Disease

Untreated dental problems and oral infections can cause drooling, trouble eating, and diarrhea. Stomatitis, gingivitis, and abscessed teeth are common issues.

Parasites

Intestinal worms and protozoal parasites like giardia can infect the gut, leading to diarrhea. Deworming medication may be needed alongside other treatment.

Chronic Diseases

Feline diabetes, hyperthyroidism, inflammatory bowel disease (IBD), liver or kidney disorders, and other illnesses may cause diarrhea. Managing the underlying condition is key to resolving diarrhea.

Cancer

Some forms of cancer, especially lymphoma or gastrointestinal tumors, can cause chronic diarrhea. Diagnostic testing is needed to confirm cancer as an underlying cause.

Medications

Antibiotics disrupt the normal gut bacteria and frequently cause diarrhea. Other medications like steroids may also trigger loose stools.

Stress

For sensitive cats, stress from travel, new environments, or schedule changes can stimulate overproduction of hormones that upset the gut. Diarrhea resulting from stress is more common with underlying IBD.

Is My Cat’s Diarrhea Serious?

While acute, mild bouts of diarrhea often resolve on their own, any persistent diarrhea lasting over 48 hours warrants a veterinary visit. Kittens, seniors, cats with chronic illness, and pregnant cats are most vulnerable to complications from unchecked diarrhea.

Signs that diarrhea requires prompt vet attention include:

• Lethargy, vomiting, loss of appetite
• Straining or inability to pass stool
• Blood or mucus in stool
• Rapid dehydration and weakness
• Fever, abdominal pain, enlarged lymph nodes
• Weight loss despite normal appetite
• Yellow or black tarry stool

Diarrhea continuing beyond 2-3 days despite home treatment, or accompanied by these concerning symptoms, can indicate potentially serious systemic illness requiring specific medical care. Don’t delay - contact your vet promptly if your cat has severe or worsening diarrhea.

What to Feed a Cat With Diarrhea

For a cat with mild diarrhea but no appetite loss, vomiting, or signs of illness, you can try the following at-home treatments:

Transition to a Bland Diet

Offer small, frequent meals of an easily digestible low-fat diet like boiled chicken, turkey, rice, potatoes or pasta. Limit fats and dairy. Refrain from treats or diet changes until stool normalizes. Ask your vet about prescription gastrointestinal diets.

Increase Fiber

Add a spoonful of canned pure pumpkin to your cat’s meals or use an over-the-counter cat fiber supplement. Start with a small amount. Too much fiber at once can make diarrhea worse.

Probiotics

Feline-specific probiotic powders or supplements containing strains like Enterococcus faecium may help restore normal gut flora. Ask your vet for dosage recommendations.

Encourage Water Intake

Dehydration occurs rapidly with diarrhea. Ensure your cat has plenty of fresh, clean water available at all times. Add more water bowls around your home if needed. Offer tuna or broth to increase fluid intake.

Monitor Litter Box

Note the frequency, volume, consistency, and color of your cat’s stool. Share any abnormal details like blood, mucus, straining, or vomiting promptly with your vet.

Diarrhea lasting over 24-48 hours in healthy adult cats, or any diarrhea in high-risk cats, requires veterinary diagnosis and treatment. Never give human anti-diarrheal medications without asking your vet, as many can be toxic for cats. With prompt care, most feline diarrhea is treatable, but severe dehydration and electrolyte imbalances can become life-threatening without medical intervention.

How Vets Diagnose the Cause of Cat Diarrhea

To determine the reason for your cat’s diarrhea, your vet will:

• Ask questions about your cat’s history, diet, environment, onset of symptoms, and any recent changes.

• Examine your cat thoroughly from nose to tail, feeling their abdomen, checking vitals, assessing dehydration, and noting any concerning symptoms.

• Run lab tests on blood, urine, and stool samples. Fecal tests check for parasites and infections. Bloodwork evaluates organ function.

• Conduct imaging tests like X-rays or ultrasound to look for foreign objects, obstructions, or masses.

• Perform additional exams such as an endoscopy to visually inspect the gastrointestinal tract.

• Consider underlying causes like chronic kidney disease, diabetes, hyperthyroidism, cancer, and IBD.

Proper diagnosis of the reason for your cat’s diarrhea is key for effective, targeted treatment. Don’t try to self-diagnose or self-treat without guidance from your vet, as you may delay essential treatment or inadvertently harm your cat. Partner with your vet to get to the bottom of your cat’s diarrhea problems.

How Is Cat Diarrhea Treated?

Treatment depends on the cause but may include:

Diet Management

Switching to an easily digestible veterinary diet, adding fiber or probiotics, feeding small frequent meals. Avoiding dietary triggers if food intolerance is the issue.

Anti-Nausea Medication

Drugs like Cerenia to control nausea and vomiting alongside diarrhea.

Antibiotics

For bacterial infections, parasites, dental infections, or inflammatory bowel disease. Probiotics may be needed to prevent antibiotic-associated diarrhea.

Anti-Inflammatories

Steroids, immunosuppressants, or other drugs to control inflammation in disorders like IBD.

IV Fluids

Fluid therapy and electrolyte supplementation for dehydration. May require hospitalization.

Surgery

To remove obstructions, foreign bodies, or masses if present. Dental extractions for severe oral infections.

Chemotherapy

For lymphoma and some gastrointestinal cancers.

Once the underlying issue is controlled, symptoms like diarrhea often resolve. Follow all at-home care instructions from your vet to help get your cat back to normal bowel movements and relief from diarrhea.

Ask Your Vet About Cat Diarrhea

• What tests will be needed to diagnose the cause?

• Are there any OTC medications that are safe to give my cat?

• Should I switch to a veterinary gastrointestinal diet?

• Are probiotics or fiber supplements advisable?

• How much water should my cat be drinking?

• How long can diarrhea safely persist before it becomes an emergency?

• Will my cat need to be hospitalized for IV fluids?

• What are the risks if my cat’s diarrhea goes untreated?

• How often should I monitor litter box changes?

• What signs warrant an urgent recheck with you?

Your vet is your partner in assessing your cat’s diarrhea causes, risks, and treatment options.

Don’t delay contacting your vet when diarrhea strikes - prompt veterinary care provides the best outcome for your cat’s health and comfort.

The Takeaway on Cat Diarrhea

Seeing ongoing diarrhea in your feline friend is always concerning.

While short-lived, mild bouts often resolve on their own, recurrent or bloody diarrhea, straining, dehydration, or other symptoms demand prompt vet attention to identify and treat the underlying cause before it becomes life-threatening.

Work closely with your vet to get your cat’s diarrhea under control and keep your cat happy and healthy.