Maybe it’s the third time this week. You switched the food, cleaned the box twice, and even swapped the litter brand, and nothing’s changed. That’s the moment most owners start googling at midnight, half-worried, half-hoping it’s nothing. Sometimes it really is small: a diet change, stress, or a hairball. But sometimes the body’s trying to say more: parasites, infection, something needing real answers, not another wait-and-see week.
In this guide, we’ll walk through the common causes, the symptoms you shouldn’t ignore, simple things that can help at home, and the point where it’s time to stop waiting and call your vet.
We at Wholsy Pets also talk about gut health and probiotics, something worth knowing since a healthy gut plays a big role in keeping diarrhoea from becoming a repeat problem.
This isn’t a replacement for veterinary advice, but it’ll help you understand what’s normal, what’s not, and what to do next.
How to Recognise Diarrhoea in Cats?
Normal cat poo tends to be firm and holds its shape. With diarrhoea, things look different; stools turn soft, loose, or watery, or start coming more often than usual. You might also notice a mucky or sore bottom, more grooming than usual around that area, or a change in toilet habits generally.
If your cat goes outdoors, spotting diarrhoea isn’t always easy, so it’s worth keeping an eye on appetite, energy levels, and general behaviour too, since those can be early clues something’s off.
What Causes Diarrhoea in Cats?
There’s rarely just one cause behind a cat’s diarrhoea. Often it starts with something simple, like a sudden change of food or sneaking a bite of something they shouldn’t have, or a bit of stress upsetting the gut.
But the list of possible causes goes further. Intestinal parasites, including worms and organisms like Giardia, are common culprits, as are bacterial or viral infections. Some medications can trigger it as a side effect, and so can inflammatory bowel conditions. Less often, diarrhoea shows up as a symptom of something happening elsewhere in the body, such as issues with the pancreas, liver, or kidneys, or even a physical blockage in the gut.
What Other Symptoms Should You Watch For?
Watch for more than what’s in the litter box. Along with diarrhoea, your cat might also throw up, eat less than usual, seem tired or low-energy, have a sore or sensitive belly, lose weight, or drink noticeably more or less water.
If your cat seems unusually quiet, is hiding away, won’t eat, or just doesn’t seem like itself, pay attention. These signs won’t tell you exactly what’s wrong, but they’ll help your vet get a clearer picture of how sick your cat really is.
How Is Cat Diarrhoea Treated?
It really depends on what’s causing it. If your cat is otherwise bright and acting like themselves, a mild bout often just needs some supportive care and a watchful eye. Keep fresh water available at all times, and resist the urge to switch up their food while their stomach’s still settling; that can make things worse, not better.
Your vet might suggest a bland or digestive-support diet, or something more targeted depending on what’s going on. If there’s a parasite, infection, medication side effect, or another condition behind it, that’s what actually needs treating; the diarrhoea itself is just the symptom.
One thing worth repeating: don’t reach for human anti-diarrhoeal medicine unless your vet has told you to use it. What’s fine for us can be genuinely dangerous for cats.
Do Probiotics for Cats Actually Help?
Probiotics are live bacteria meant to help restore balance in the gut, and they’re often brought up when a cat’s normal digestive flora has been thrown off, including in some diarrhoea cases.
That said, they’re not a cure-all. PDSA’s guidance is clear that probiotics for cats work for some cats and not others, and it really comes down to the individual case. If your cat’s diarrhoea is sticking around, a probiotic on its own isn’t enough; you still need to figure out why it’s happening.
If you do want to try one, pick a product made specifically for cats, and follow the dosing your vet or the packaging recommends.
When Should You Actually Call the Vet?
A single loose stool isn’t necessarily cause for panic, but don’t just sit and wait if your cat isn’t bouncing back. PDSA recommends calling a vet if mild diarrhoea hasn’t cleared up within a day, gets worse, or shows up alongside other symptoms.
Get in touch with your vet sooner rather than later if you notice:
- Diarrhoea that won’t stop or keeps returning
- Blood or a good amount of mucus in the stool
- Vomiting repeatedly
- Weak or unusually tired
- A sore or tender belly
- Eating or drinking much less than usual
- Any signs of dehydration
- Diarrhoea that began after a new medication
- A kitten or older cat with diarrhoea
And if you think your cat has swallowed something dangerous or something that could block their gut, don’t wait around to see if symptoms show up call your vet right away.
How Do Vets Figure Out the Cause?
Usually, it starts with questions: diet, any recent changes, medications, other symptoms, and general behaviour, followed by a physical exam. From there, depending on what they find, they may run stool tests, bloodwork, imaging, or other diagnostics. What’s needed varies from cat to cat.
Quick Answers
1. Can probiotics for cats help with diarrhoea?
Sometimes, especially if gut bacteria have been disrupted, they’re not a substitute for finding out what’s actually wrong.
2. My cat has diarrhoea but otherwise seems fine what now?
Keep water available, watch their stool and behaviour, and don’t change their food suddenly. Call your vet if it doesn’t clear up or other symptoms appear.
3. How long does cat diarrhoea usually last?
If your cat doesn’t show any improvement after 24 hours, you should seek professional help. If your cat is unwell, it is important to consult a veterinarian.
4. Is blood in the stool serious?
Yes, you need to always raise this issue to your vet, especially if your cat is either ill or young.
5. What shouldn’t I give my cat for diarrhoea?
Do not give human drugs unless your veterinarian has directed you to do so. The therapy must be appropriate for the specific cause.