Why Cats Get Diarrhoea
Diarrhoea is one of the most common reasons cat owners seek veterinary advice. In most cases it resolves within a day or two with minimal intervention. In some cats it becomes a persistent or recurring problem that's hard to pin down and harder to resolve. Understanding what drives it, and the role the gut microbiome plays, is the key to managing it effectively.
Common Causes of Diarrhoea in Cats
Dietary change. Cats are more sensitive to dietary change than dogs. Switching from one food to another, even within the same brand, can disrupt the gut microbiome enough to produce loose stools within 24 to 48 hours. Transitions should always be made gradually over 10 to 14 days.
Dietary indiscretion. Hunting and eating prey animals, scavenging, or getting into inappropriate food. The gut responds to unfamiliar or contaminated content with rapid expulsion.
Stress. The feline gut-brain axis is particularly sensitive. Changes in household routine, new pets, moving, travel, or any disruption to the sense of predictability that cats depend on can produce diarrhoea within hours. This is one of the most underrecognised causes of cat diarrhoea and one of the most significant drivers of chronic gut disruption.
Antibiotics and medication. A single antibiotic course can substantially reduce gut microbial diversity in cats. The resulting dysbiosis produces loose stools that may persist for weeks after the antibiotic course ends without active gut restoration.
Parasites. Giardia is among the most common parasitic causes of persistent diarrhoea in cats, particularly in multi-cat households or cats with outdoor access. Tritrichomonas and roundworms are also frequent culprits. Requires veterinary diagnosis and specific treatment.
Food intolerance or allergy. Immune reactions to specific proteins produce chronic diarrhoea that doesn't respond to symptomatic treatment because the trigger remains in the diet. Diagnosis requires an elimination diet trial.
Inflammatory bowel disease (IBD). A common cause of chronic or recurring diarrhoea in adult and senior cats. The gut lining is chronically inflamed, disrupting normal digestion and absorption. Requires veterinary diagnosis and ongoing management.
Hyperthyroidism. A very common condition in senior cats that speeds up gut motility and produces chronic loose stools alongside weight loss despite a good appetite. Resolves with thyroid management.
When to See a Vet
See your vet if the diarrhoea contains blood or is very dark, if it has lasted more than 48 hours without clear improvement, if the cat is also vomiting, not eating, or showing signs of dehydration, if the cat is a kitten, senior, or immunocompromised, or if you suspect parasites. Cats dehydrate more rapidly than dogs and younger and older cats are particularly vulnerable.
Gut Health Support for Cats with Diarrhoea
Probiotic and postbiotic supplementation restores the beneficial bacterial community disrupted by diarrhoea's most common causes and helps rebuild the gut lining integrity that stress, infection, and antibiotic use damage. Starting during the episode supports faster recovery. Continuing after recovery reduces the likelihood of recurrence.
Tummy Time Liquid Probiotics for Dogs and Cats (500ml)
The liquid format makes Tummy Time the most practical way to give a cat gut health support during and after a diarrhoea episode. Pour the appropriate amount over a small amount of wet food. The Zoonatant postbiotic technology helps support the gut lining and inhibit harmful pathogens contributing to the symptoms. Most cats accept it without detecting it in their food.
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Frequently Asked Questions
How long is normal for cat diarrhoea to last?
Acute diarrhoea from a temporary disruption like a dietary change or mild infection typically resolves within 24 to 48 hours. If it hasn't improved by 48 hours, or worsened at any point, a vet visit is appropriate.
Should I withhold food if my cat has diarrhoea?
A brief period of gut rest is generally appropriate for adult cats with acute diarrhoea. Offer small amounts of highly digestible food rather than withholding food entirely. Kittens and senior cats should not be fasted without veterinary guidance as they can deteriorate quickly.
Can stress cause diarrhoea in cats?
Yes, and this is one of the most common but least recognised causes. The feline gut-brain axis is highly responsive to stress. Any disruption to a cat's environment or routine can produce diarrhoea. Gut microbiome support reduces the severity and duration of stress-induced diarrhoea by building a more resilient gut.
My cat keeps getting diarrhoea. What should I do?
Recurring diarrhoea warrants veterinary investigation to rule out parasites, IBD, hyperthyroidism, and food intolerance. Alongside that, daily probiotic and postbiotic supplementation supports gut microbiome resilience and reduces the frequency of episodes driven by chronic dysbiosis.