Why Do Cats Have Diarrhea? A Complete Guide for Cat Owners

Finding loose, watery stools in your cat’s litter box can be alarming. As a cat owner, you’re probably wondering why do cats have diarrhea, especially if they seem otherwise normal. While occasional digestive upset happens to most cats, identifying the underlying cause and knowing when to adapt veterinary care can make all the difference in your feline friend’s health.

Diarrhea can happen to cats of any age, but it’s especially worrisome for kittens, older cats, and those with weaker immune systems. The following advice will help you understand the causes, recognize different types, and know when it’s time to call your vet.

Why Do Cats Have Diarrhea

DIETARY ISSUES

Sudden Food Changes
Cats have sensitive gastrointestinal tracts. Switching foods too quickly is one common underlying cause that can shock the GI tract, leading to loose stools or mild diarrhoea. Even high-quality foods can cause problems if introduced abruptly.

Treats and Table Scraps
While your cat might give you those irresistible eyes at dinner, human food often contains ingredients that don’t agree with feline stomachs. Rich, fatty, or unfamiliar foods can trigger digestive upset.

Garbage and Spoiled Food
Curious cats sometimes investigate garbage cans or eat food that’s past its prime. Spoiled food contains bacteria that can wreak havoc on your cat’s digestive system.

Does Wet Cat Food Cause Diarrhea?
Wet food itself typically does not cause diarrhea in cats. However, swiWet food usually doesn’t cause diarrhea in cats. However, if you switch from dry to wet food too quickly or choose a recipe with ingredients to which your cat is intolerant, it may upset their stomach. Some cats are also sensitive to certain proteins or additives in wet food. A problem can be a food allergy, and taking a closer look at your cat’s diet with the help of a veterinarian can help resolve these issues.

Common Causes Of Diarrhea In Cats

INFECTIONS

Viral Infection
Young cats and unvaccinated adults are particularly susceptible to viral infections that can cause severe or watery diarrhea, which can significantly affect a cat’s health. These infections often present with additional symptoms, such as lethargy, vomiting, or fever.

Bacterial Infections
Inflammation and loose stool might result from harmful germs growing in your cat’s intestines. These illnesses can occasionally arise from consuming contaminated food or water.

Parasitic Infections
Internal parasites are sneaky culprits. Intestinal worms, roundworms, tapeworms, coccidia, and Giardia can all trigger feline diarrhea. Even indoor cats can be affected if parasites are transmitted through insects or contaminated items brought into the home. For the purpose of both detection and prevention, routine veterinarian care is crucial.

Stress and Anxiety
Cats are creatures of habit. Major changes in their environment can manifest as physical symptoms, including diarrhea. Moving to a new home, introducing new pets, or rearranging furniture can cause enough stress in sensitive cats to lead to digestive upset or diarrhea.

INFLAMMATORY DISORDERS

Inflammatory Bowel Disease (IBD)
This chronic condition causes ongoing inflammation in your cat’s digestive tract. Cats with IBD often experience recurring episodes of diarrhea, sometimes accompanied by vomiting or weight loss.

Colitis
Lower bowel irritation can cause frequent, urgent bowel movements with mucus or small amounts of blood. This condition is particularly uncomfortable for cats and may indicate an underlying health issue.

METABOLIC DISEASES

Liver Disease
When your cat’s liver isn’t functioning properly, it affects their entire digestive system. Liver problems can cause diarrhea that is yellow in color and require immediate veterinary care.

Pancreatic Disorders
The pancreas produces enzymes essential for digestion. When it’s inflamed or not functioning correctly, your cat may experience diarrhea, along with other symptoms such as vomiting or abdominal pain.

Thyroid Imbalances
Hyperthyroidism is a common condition in adult cats, which can accelerate their metabolism and lead to digestive upset. Cats that experience thyroid imbalance often lose weight despite eating more, and they may exhibit frequent loose stools.

Medications and Toxins
The normal balance of bacteria in your cat’s intestines can be disrupted by the use of antibiotics. While necessary for treating infections, they sometimes cause temporary diarrhea. Other medications and household toxins can also trigger digestive problems.

Constipation Paradox
This might surprise you, but severely constipated cats sometimes pass liquid stools around hard, impacted feces. This is particularly common in older cats with mobility issues or those who aren’t drinking enough water.

Identifying the Type and Severity of Diarrhea in Cats

ACUTE VS. CHRONIC DIARRHEA

Acute diarrhea appears suddenly and lasts less than two weeks. It’s often caused by dietary indiscretion, mild infections, or stress.
Chronic diarrhea persists for weeks or recurs frequently. This type usually indicates an underlying cause or health condition that requires veterinary care.

COLOR AND CONTENT MATTER

Yellow Diarrhea
Yellow stools can indicate liver problems, certain bacterial infections, or rapid transit through the intestines. This color change warrants veterinary attention to identify the underlying cause.

Blood in Stool
Dark, tarry blood suggests upper intestinal bleeding, while bright red blood indicates lower intestinal irritation. Both require immediate veterinary care and can be signs of bloody diarrhea.

Mucus-Coated Stool
Slimy, mucus-covered feces often indicate inflammation in the lower part of the intestinal tract. While not always serious, it’s worth monitoring closely, as it may point to an underlying cause.

ADDITIONAL SYMPTOMS TO WATCH

Diarrhea becomes more concerning when accompanied by:

Vomiting
Loss of appetite
Lethargy or weakness
Fever
Dehydration (dry gums, sunken eyes)
Abdominal pain

When To Be Concerned With A Vet

The question “Why do cats have diarrhea but are acting normal?” is common. Even if your cat seems fine, certain situations require professional attention and may signal an underlying cause:

IMMEDIATE VETERINARY CARE NEEDED:

Diarrhea lasting more than 24 hours
Blood in stool (bright red or dark/tarry), possible bloody diarrhea
Vomiting alongside diarrhea
Signs of dehydration
Kittens under six months old
Senior cats with chronic health conditions
Multiple episodes in quick succession

EMERGENCY CARE SITUATIONS:

Severe dehydration
Inability to keep food or water down
Extreme lethargy
Signs of pain or distress
Suspected toxin ingestion

MONITOR AT HOME IF:

Single episode with no other symptoms
Adult cat
No blood or concerning colors
Normal appetite and energy

Home Care and Management

CATS DIET ADJUSTMENTS

Provide a Bland Diet
When your vet approves home care, offer easily digestible foods. Boiled chicken (without skin or bones) paired with plain rice can help settle an upset stomach. Low-fat cottage cheese or plain yogurt with live cultures may also help.

Smaller, Frequent Meals
Serve four smaller meals throughout the day rather than two huge ones. This reduces digestive stress and facilitates the more efficient absorption of nutrients.

Consider Fiber Supplements
Adding fiber can help firm up loose stools. Plain canned pumpkin (not pie filling) is an excellent source of digestive fiber that most cats tolerate well.

Hydration is Critical
Liquid or watery diarrhea can quickly dehydrate animals. Make sure your feline always has access to clean water. Some cats prefer running water from fountains or faucets. You can also try adding a little low-sodium chicken broth to encourage drinking.

Probiotics for Gut Health
Veterinary-approved probiotics can help restore beneficial gut bacteria, especially after antibiotic treatment or digestive upset. These supplements support the natural microbiome that keeps your cat’s digestive system healthy.

WHEN NOT TO TREAT AT HOME

Never attempt home treatment if:

Your cat is vomiting
You suspect poisoning
There’s blood in the stool
Your cat shows signs of severe illness
Diarrhea persists beyond 24 hours
There are signs of intestinal parasites

Critical Warning: Never give your cat human medications, such as Imodium or Pepto-Bismol. These can be toxic to cats and may worsen their condition or mask serious symptoms.

Veterinary Treatments for Feline Diarrhea

Diagnostic Testing

Fecal Examinations
Your veterinarian will test stool samples for parasites, bacteria, and other infectious agents, such as intestinal worms and parasites. Sometimes multiple samples are needed, as parasites don’t always show up in every test.

Blood Work
Comprehensive blood panels can reveal metabolic diseases, organ dysfunction, or systemic infections. These examinations help identify the underlying cause of diarrhea.

Imaging Studies
X-rays or ultrasounds might be necessary to check for obstructions, tumors, or structural abnormalities.

Treatment Options

Anti-Diarrheal Medications
Veterinary-prescribed medications can help slow intestinal motility and firm up stools. These are different from human medications and specifically formulated for cats.

Antibiotics
If bacterial infection is suspected or confirmed, your vet may prescribe targeted antibiotics. These medications require careful monitoring to prevent further digestive upset.

Fluid Therapy
Dehydrated cats may need intravenous or subcutaneous fluids to restore proper hydration levels. This treatment is often necessary for severe cases.

Prevention Strategies for Cats' Diarrhea

Proper Diet Management

Gradual Food Changes
When switching foods, transition slowly over 7-10 days. Utilize a combination of increasing quantities of the new food and decreasing quantities of the old food. Always consider the cat’s diet when managing or preventing digestive concerns.

Quality Nutrition
Select premium cat food that is specifically designed for your pet’s age and health status. Avoid frequent diet changes unless medically necessary or advised after veterinary care.

Treat Moderation
Limit treats to no more than 10% of your cat’s daily calories. Stick to cat-specific treats rather than human food.

Regular Parasite Prevention

Deworming Schedules
Follow your vet’s recommendations for regular deworming, especially for cats who go outdoors or live with other pets.

Fecal Testing
Annual or semiannual fecal examinations can detect parasite infections before they become more severe problems.

Stress Reduction

Environmental Stability
Maintain consistent routines and environments when possible. If changes are necessary, introduce them gradually to prevent unnecessary digestive upset.

Safe Spaces
Provide quiet, comfortable areas where your cat can retreat when feeling overwhelmed.

Enrichment Activities
Mental stimulation through toys, climbing structures, and interactive play can reduce stress-related health issues.

Vaccination Programs
Maintain your cat’s vaccinations up to date to prevent viral infections that can cause diarrhea. Your vet can suggest a vaccination schedule tailored to your cat’s lifestyle and risk factors.

When Home Care Works for Your Feline

With proper management, mild diarrhoea or other less serious digestive problems often resolve within 24-48 hours. Success signs include:

Firming stools
Normal appetite returning
Maintained energy levels
No additional symptoms are developing

However, contact your veterinarian immediately if symptoms worsen or new concerns arise. Multiple episodes of severe symptoms or recurring digestive upset should always prompt professional veterinary care and investigation into the possible underlying cause.

Taking Action for Your Cat's Health

Understanding why your cat has diarrhea empowers you to provide better care for your feline companion. While occasional digestive upset is normal, persistent or severe symptoms always warrant veterinary care. Remember that early intervention can prevent small problems from developing into severe health issues.

The key to managing cat diarrhea lies in knowing when to monitor at home and when to seek veterinary care. If something seems wrong, don’t hesitate to contact your veterinarian for guidance or, in critical cases, emergency care.

By staying informed about potential causes, maintaining preventive care, and responding appropriately to symptoms, you can help ensure your cat maintains optimal digestive health throughout their life. Your vigilance and quick action can make the difference between a minor digestive upset and a serious health crisis.