Cat diarrhea: causes, what to do, and when to see a vet
Most loose stools clear up in a day or two. Here’s how to tell when it’s more than an upset stomach, and what to keep track of in the meantime.
The Petumi team · Updated · 2 min read
Quick answer
Short bouts of diarrhea in an adult cat that is still eating, drinking and acting normally are often caused by a food change or stress, and usually settle within a day or two. Keep fresh water out, don’t give human medicine, and call your vet if it lasts more than two days or comes with any of the signs below.
When to call the vet
Call your vet today if
- There’s blood in the stool, or it’s black and tarry
- Your cat is also vomiting, weak, hiding, or not eating
- It’s a kitten, a senior cat, or a cat with a health condition
- It has lasted more than two days, or hasn’t improved with home care
- You think your cat ate something toxic, like a plant or a chemical
Common causes
Diarrhea is a sign, not a diagnosis. These are the causes vets see most often.
| Cause | What you might notice | What usually helps |
|---|---|---|
| Food change | It started a few days after a new food or treat | Go back to the old food, then switch over 7–10 days |
| Stress | A move, a long car ride, a new pet, a vet visit | A quiet space and the usual routine; it often passes on its own |
| Parasites | Common in kittens and cats that go outside; may come and go | A stool test and the right dewormer from your vet |
| Something toxic | Plants, chemicals, or something from the trash | Call your vet now, especially if you saw what it was |
| Ongoing illness | It keeps coming back, weight loss, an older cat | A vet exam; causes like inflammatory bowel disease or an overactive thyroid need treatment |
Kittens can also get loose stools while they get used to solid food. Because they dehydrate faster than adults, call your vet sooner rather than later.
What you can do at home
- Keep fresh water within easy reach. Diarrhea dehydrates cats quickly.
- Don’t give human medicine. Some over-the-counter products are harmful to cats.
- Don’t take food away for long without asking your vet first.
- If a new food is the likely cause, go back to the old one. When the stool is normal again, switch over 7–10 days.
- Keep the litter box clean so you can see whether things are getting better.
What to write down for your vet
Your vet will want to know your cat’s age and how bad it is. A few notes make the call much faster:
- When it started, and how many times a day it happens
- What it looks like: soft or watery, the color, any blood or mucus
- Whether your cat is eating, drinking, vomiting, or less active than usual
- Anything new: food, treats, medicine, a move, a new pet
Loose stool · MarchFAQ
How long can a cat have diarrhea before seeing a vet?
If your cat is an adult and otherwise eating, drinking and acting normally, call your vet if it hasn’t improved within two days. Call right away for kittens, senior cats, or any of the warning signs on this page.
Can I give my cat Pepto-Bismol or other human medicine?
No. Some over-the-counter medicines are harmful to cats. Don’t give your cat anything, including probiotics, unless your vet recommends it.
Should I stop feeding my cat?
Not without asking your vet. For an otherwise healthy adult cat, your vet may suggest a short break from food or small meals of a gentle diet, but cats shouldn’t go without food for long.
Can stress give my cat diarrhea?
Yes. A move, a long car ride, a new pet or a stay at the vet can cause a short bout that settles once things are calm again.
Sources
- Diarrhea, Cornell Feline Health Center
- Diarrhea in Cats, VCA Animal Hospitals
This guide is general information, not a diagnosis. If you’re worried about your pet, call your vet.
Keep track together
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