You walked over to the litter box expecting the usual scoop, and instead you found loose or watery stool. Your cat, meanwhile, is acting like nothing happened.
A single bout of diarrhea in a cat who is still eating, drinking, and behaving normally is usually not an emergency, and most cases clear up within a day or two. What you want to watch is whether it continues, clears up and then returns, or shows up alongside other symptoms.
What Changed in the Last 72 Hours?
When a cat has diarrhea but otherwise feels fine, the cause is often something recent. Think back over the last two or three days.
- A change in their regular food or formula
- New treats or table scraps
- Got into the trash or ate something they weren’t supposed to
- Recent flea or worm medication
- Antibiotics or another new prescription
- New supplement or vitamin
- New litter or a moved litter box
- New pet, visitor, or houseguest
- Travel, boarding, or a vet visit
- Fireworks, storms, or construction
- Moved furniture or a change in routine
If something on this list changed right before the diarrhea started, that’s a likely trigger. In most cases, the stool firms back up on its own within a day or two.
When Should You Worry About Cat Diarrhea?
If your cat is still eating, drinking, moving around normally, and showing no other symptoms, a mild case of diarrhea can usually be monitored at home for a day or two.
- Kittens under 6 months: Call the vet if the diarrhea continues for 24 hours.
- Healthy adult cats: Call if it hasn’t improved within 48 hours.
- Senior cats or cats with an existing health condition: Call if it continues for 24 hours.
Call your vet right away if your cat develops any of the following along with diarrhea:
- Repeated vomiting
- Refusing food or water
- Lethargy, hiding, weakness, or a hunched posture
- Signs of dehydration, such as dry or tacky gums
- More than a small streak of blood, or blood that keeps appearing
- Black, tarry stool
- Very frequent or completely watery diarrhea
- You think they may have eaten something toxic or swallowed a foreign object
What Different Stool Colors Mean
The color of the stool can give you a few more clues about what is going on.
| Color | What It Can Mean |
|---|---|
| Brown or tan | Usually within the normal color range. |
| Yellow | Stool may be moving through the intestines too quickly for bile to break down normally. |
| Green | Can come from eating grass or from bile moving quickly through the digestive tract. |
| Bright red streaks | Usually points to bleeding or irritation in the lower digestive tract. |
| Black and tarry | Can indicate digested blood from higher in the digestive tract. |
| Pale or gray | Can be associated with problems involving bile, the liver, or pancreas. |
| Mucus-coated | Often points to irritation in the colon and can also occur with parasites. |
What to Do at Home for the First 24–48 Hours
Keep Them Eating
Don’t fast a cat with diarrhea unless your vet tells you to. Continue feeding, but divide their food into three or four smaller meals throughout the day.
Skip treats, table scraps, rich foods, and anything new until the diarrhea clears.
Keep Them Hydrated
Keep fresh water available and make sure your cat is actually drinking. Don’t switch to wet food just to increase their water intake. A new food during a bout of diarrhea can make things worse, so stick with what they normally eat, wet or dry.
You can also spot early signs of dehydration by checking their gums. They should feel moist, not dry or tacky.
When Cat Diarrhea Keeps Coming Back
A one-time bout of diarrhea is different from soft stool that keeps returning. If there hasn’t been a recent food, medication, or routine change and the problem keeps coming back, it’s worth looking for an ongoing cause.
Parasites
Roundworms, hookworms, Giardia, coccidia, and other intestinal parasites can cause recurring diarrhea even when a cat seems fine between episodes. Indoor cats can pick them up too through fleas, contaminated soil tracked in on shoes, other pets, or mice and insects that make it into the house.
Food Sensitivities
If soft stool keeps coming back while your cat is eating the same food, a food sensitivity may be involved. This is different from the temporary upset that can happen after a sudden food change.
Chronic Digestive or Health Problems
Diarrhea that keeps returning can also occur with chronic intestinal inflammation and conditions such as hyperthyroidism, kidney disease, liver disease, or pancreatic problems. These become more concerning when the diarrhea comes with weight loss, vomiting, appetite changes, or increased thirst.
If your cat regularly has soft stool or the diarrhea keeps returning, make an appointment with your vet even if they seem normal otherwise.
FAQ
How long does cat diarrhea usually last?
A mild bout of diarrhea in an otherwise healthy adult cat often clears within a day or two. If it hasn’t improved within 48 hours, call your vet. Kittens, senior cats, and cats with existing health problems should be checked sooner.
My cat has diarrhea but is eating and drinking normally. Do I still need to see the vet?
Not necessarily. If your cat is eating, drinking, and behaving normally, you can usually watch a mild case for a day or two. Call your vet sooner if the diarrhea becomes severe or other symptoms appear.
Why does my cat have diarrhea all of a sudden?
Sudden diarrhea is often linked to a change in food, treats, medication, or routine, or to something your cat ate that they shouldn’t have. Stress can also cause short-term diarrhea.
Should I fast my cat if they have diarrhea?
No, not unless your vet tells you to. Keep feeding your cat, but divide their food into smaller meals until the diarrhea clears.
Can I give my cat Imodium or Pepto-Bismol?
Don’t give either one unless your vet tells you to. Imodium requires careful dosing in cats, and Pepto-Bismol should not be given without veterinary guidance.
Can indoor cats get parasites?
Yes. Indoor cats can still pick up intestinal parasites through fleas, contaminated soil tracked in on shoes, other pets, or mice and insects that make it into the house.
Can stress alone cause diarrhea in cats?
Yes. A move, new pet, visitors, boarding, a vet visit, fireworks, or another disruption to their routine can trigger short-term diarrhea.
Is diarrhea normal after flea or worm treatment?
Diarrhea can happen after some flea or deworming medications. If it is severe, doesn’t improve, or comes with vomiting, weakness, tremors, or other unusual symptoms, call your vet.
Debbie Reid is the founder and chief editor of CatPedia.net, with over 25 years of hands-on experience in feline care, rescue, and behavior research. Inspired by her rescue cats Snickers and Bigboy, she collaborates with animal welfare resources and consults veterinary literature to turn complex feline health, nutrition, and behavior topics into clear, actionable guides.
