Why Your Cat Has Diarrhea and What to Do About It

Discovering your cat has made a mess in their litterbox is never a good start to the day, and it’s even worse to find they didn’t make it in time. Perhaps it was the new bag of treats, or the unexpected visit from a noisy friend causing an upset tummy. But while diarrhea is never a fun surprise, when is it a cause for concern? In this article we’ll explore what causes diarrhea in cats, what you can do at home, and when it’s time to take a trip to the vet.

Cat Has Diarrhea? Fast Facts:

• One episode of diarrhea may not be serious
• Diet changes, stress, and parasites are all common causes
• Avoid dehydration by providing lots of fresh water
• See a vet if diarrhea lasts more than 24-28 hours, or if you notice blood, vomiting, or lethargy

What Diarrhea Really Means

Diarrhea is caused by an imbalance in the digestive tract, be it infection, irritation, or a change in the way your cat is processing food. Soft, loose, watery, or frequent bowel movements which may be uncomfortable for your kitty to pass are all diarrhea. There are two main types your cat may experience:

• Acute - Sudden onset, usually due to diet or stress
• Chronic - Lasting 2 weeks or more, usually due to allergies, parasites, or underlying illness

Do I need to worry if my cat has diarrhea but is otherwise fine? It’s important to remember that diarrhea is not an illness, but a symptom which can lead to further problems like dehydration. So even if your cat seems otherwise happy and healthy it’s important to speak to a vet if your cat is experiencing on-going or frequent diarrhea to find and treat the cause.

Common Reasons Your Cat Has Diarrhea

Sudden Diet Changes: Cats’ digestive systems don’t handle change well. Changing the brand of food or the protein source can cause diarrhea. Instead, slowly change foods over the course of a week or more.

Food Intolerance or Sensitivity: Chicken, beef, dairy, and some grains are common triggers. You may see recurring soft stools, gas, and bloating. An elimination diet directed by your vet can help identify problem ingredients.

Eating Something They Shouldn’t: Fun forbidden snacks like plants, garbage, or human food can cause diarrhea. Mild cases should resolve quickly, but more serious mistakes like string or toxin ingestion are emergencies.

Parasites (Worms, Giardia, Coccidia): Kittens, outdoor cats, and rescues are all at higher risk. Parasites can cause soft stools, mucus, occasional blood, and weight loss. Your vet may ask for a fecal sample to diagnose and prescribe the correct treatment.

Stress or Anxiety: Stress can change the gut microbiome or overall motility. Cats can be stressed by moving or renovations, a new pet, or house guests. You can reduce stress by providing calm, secure spaces and using pheromone diffusers.

Infections (Bacterial or Viral): Salmonella, Campylobacter, or viruses like panleukopenia can all cause diarrhea. Cats may also have a fever, lethargy, or poor appetite. Infections require diagnosis and supportive treatment with your vet.

Underlying Health Conditions: Chronic diarrhea can be caused by Irritable Bowel Disease (IBD), liver or kidney disease, or hyperthyroidism. Although rare, some cancers can cause chronic diarrhea. Your vet will investigate through blood-work or imaging as appropriate.

When To See The Vet

• Diarrhea lasts more than 24-48 hours
• Diarrhea includes blood or mucus, or is black/tarry
• Refusing to eat and/or frequent vomiting 
• Hiding away, lethargy, or dehydration 
• Weight loss
• Changes in thirst or urination
• Your cat is a kitten, senior cat, or has a chronic illness

It’s important to remember that watery diarrhea, vomiting, or refusal to eat/drink can quickly lead to dehydration. Call your vet immediately if these symptoms appear.

What You Can Do At Home (For Mild Cases)

Can I help my cat with diarrhea without a stressful trip to the vet? In some cases, you can! If your cat has only had a single or very mild bout of diarrhea you can try these steps to help them get back to normal:

• A short period of fasting (with water always available!) can help rest and reset the digestive tract. Remember that kittens and elderly cats should never be fasted as this can cause an unsafe drop in blood sugar. For this reason diabetic cats should also never be fasted. 
• What should I feed my cat with diarrhea? Provide a bland diet which is easy to digest. Boiled chicken and plain white rice, or prescription GI diets are both good options. As your cat’s stool begins to firm up you can slowly transition over 7 to 10 days back to normal food.
• Keep your cat hydrated by providing clean bowls of fresh water away from food, or cat-safe electrolyte solutions. Wet food can help boost hydration. 
• Make sure the litterbox stays as clean as possible and easy to access. Frequent scooping helps monitor your cat’s symptoms. 

If despite your support your cat’s diarrhea doesn’t resolve or worsens, it’s time to phone the vet.

How Vets Diagnose The Cause

You vet visit should start with a clinical exam. A good top-to-tail can help identify issues like pain, dehydration, and overall body condition, as well as other signs that might point to the cause. Depending on what they find your vet will then recommend further testing. Fecal tests will check for parasites, bacteria, and inflammation. Thyroid, kidney, and liver issues can all be diagnoses through blood-work, as well as more subtle metabolic issues like imbalances in micro-nutrients like folate and cobalamin. Imaging including x-rays or ultrasound can help rule out cancers or blockages in the gut, and assess whether IBD is a likely culprit. They may recommend a diet trial to identify or confirm suspected allergies or food sensitivities.

Treatment Options

Once a cause has been identified, your vet will recommend a treatment plan. Possible options include:

• Prescription dewormers or anti-protozoal medications to deal with parasites
• Antibiotics, fluids and dietary support to address infection
• Hypoallergenic or hydrolyzed diet to address allergies/sensitivities
• Anti-inflammatory medications (like steroid), probiotics, and restricted diets to address IBD
• Environmental adjustments, pheromone diffusers, and enrichment plans to address stress

Preventing Future Diarrhea

Once your cat is on the mend, there are steps you can take to help their recovery and avoid future incidents. Always transition foods slowly over the course of 7 to 10 days rather than all at once. New treats should be added sparingly until you know how your cat handles them. A balanced, high-quality diet will keep the gut happy. Make sure curious kitties don’t have access to toxic plants, chemicals, or table-scraps that can land them in trouble. Plan ahead for travel and other big changes to minimize stress. Year-round parasite prevention helps avoid worms and protozoal infections and a yearly vet visit can catch any concerns early.

Final Thoughts

Most cases of feline diarrhea are temporary and will resolve with the correct supportive treatment. Remember that hydration, close monitoring, and early intervention with a vet for on-going diarrhea are key to resolution. Whether it’s something they ate, an infection, or a stressy tummy, your vet can track down the cause and get to work getting your cat’s tract back on track.

FAQs

Author Bio

Caitlin Merrill MRCVS, BVMS, BS ASci, MLitt

Caitlin is a primary care clinician based at the University of Glasgow. She currently splits her time between clinical work, teaching, and writing. When not working she can be found hiking the moors with her mildly dramatic terrier or cuddling on the sofa with her wildly naughty cat.

Feature image: istockphoto