Cat diarrhea: causes, home care and when to see a vet
Check these signs first
- Red flag: Go to the vet right away if your cat6 signs
- Yellow flag: Make an appointment within the next few days if4 signs
- Green flag: What to do at home if it's mild
- Typical cost
- about $85-$160
- Reading time
- 5 min
- Sources
- 6
- Updated
A bout of mild diarrhea lasting a day or two in an adult cat who keeps eating, drinking and playing is usually caused by something that didn't agree with them and clears up on its own. But cats need closer watching than dogs: they dehydrate quickly, shouldn't go long without eating, and diarrhea in a kitten or a senior cat can be the first sign of something serious.
Common causes
- A sudden food change: switching food overnight is one of the most common causes. Changes should be gradual, over 7-10 days.
- Something they shouldn't have eaten: milk (most adult cats don't digest lactose well), human food, plants or garbage.
- Intestinal parasites: worms, giardia or coccidia. Very common in kittens, outdoor cats and cats from shelters.
- Stress: moving, a new pet, travel or houseguests can upset their gut.
- A food intolerance or allergy, which tends to cause on-and-off diarrhea or vomiting for weeks.
- Viral or bacterial infections. The most serious is feline panleukopenia (feline distemper), which mainly affects unvaccinated kittens and can be fatal.
- Chronic illnesses: inflammatory bowel disease, hyperthyroidism or intestinal lymphoma, more common in middle-aged and older cats.
- Toxins or human medications. Never give a cat acetaminophen (Tylenol) or other human medicines.
Where is it coming from? What you can observe
Noticing what the diarrhea looks like helps your vet a lot:
| Small intestine | Large intestine (colon) | |
|---|---|---|
| Amount | Large amount each time | Small amount each time |
| How often | Normal or slightly more | Many times a day, urgently |
| Mucus | Little or none | Common |
| Blood | Dark, black stool | Red, fresh |
| Straining | Little | Often strains |
| Weight loss | Common if it drags on | Uncommon |
If you can, take a photo of the stool and note how many times your cat used the litter box. If you're going to the vet, bring a fresh sample in a clean container.
What to do at home if it's mild
If your cat is an adult, the diarrhea started less than 24-48 hours ago and they're still active, eating and drinking:
- Keep fresh water within reach. If they drink little, try several bowls or a water fountain.
- Don't withhold food for long. Unlike dogs, a cat shouldn't go more than 24 hours without eating: fasting can trigger a serious liver disease (hepatic lipidosis), especially in overweight cats.
- Offer small, frequent meals of their usual food or, better, a veterinary gastrointestinal diet. For a day or two you can also offer plain cooked chicken or turkey, skinless, boneless and unseasoned.
- Don't give human anti-diarrhea medicines or home remedies without asking your vet.
- Scoop the litter box often and wash your hands: some parasites can spread to other cats in the home.
If it doesn't improve within 48 hours, or any of the signs below appear, take your cat to the vet.
When to see the vet
Go to the vet right away if your cat:
- Is a kitten (especially under 6 months or unvaccinated). Kittens dehydrate very fast.
- Has diarrhea and vomiting together, or vomits and can't keep water down.
- Has a lot of blood in the stool or black stool.
- Is lethargic, hiding or hasn't eaten for more than 24 hours (read what to do if your cat isn't eating and is hiding).
- Has dry or tacky gums, or skin on the neck that's slow to fall back when gently lifted: signs of dehydration.
- May have eaten a toxic plant (like lilies), a medication or a cleaning product.
Make an appointment within the next few days if:
- The diarrhea lasts more than 2-3 days, even if your cat seems fine.
- It comes and goes over weeks.
- Your cat is losing weight, or eating a lot but getting thinner.
- Your cat is over 8 and the diarrhea is new.
What the vet will do
After an exam and checking for dehydration, the usual first step is a fecal test to look for parasites (including giardia). Depending on the case, your vet may recommend bloodwork (with a thyroid test in older cats), an abdominal ultrasound or an elimination diet for several weeks if a food allergy is suspected. Dehydrated cats get fluids. In the US, an exam costs about $57-$130 and a fecal test about $29 on average (Synchrony/CareCredit 2025-2026 cost study).
Frequently asked questions
How long can cat diarrhea last?
A mild episode from something that disagreed with them usually resolves in 24-48 hours. If it lasts more than 2-3 days, keeps coming back or your cat seems unwell, see your vet. Diarrhea lasting more than 2-3 weeks is considered chronic and needs a workup.
Can I give my cat chicken and rice for diarrhea?
Plain cooked chicken can help for a day or two. Rice isn't necessary: cats are carnivores and get little out of it. The best option is a gastrointestinal diet made for cats, which your vet can recommend.
Can my cat's diarrhea spread to other pets or to me?
Some causes can, such as certain parasites (like giardia) or infections. Scoop the litter box daily, wash your hands afterward and, if you have several cats, ask your vet whether they should all be checked.
Is it normal for a new kitten to have diarrhea?
It's common, from the stress of the move and new food, but parasites are also likely. Take your kitten to the vet early for deworming and vaccines, and make sure they eat and drink: in a kitten, diarrhea always deserves a vet visit.
Sources
- Diarrhea in Cats (VCA Animal Hospitals)
- Feline Panleukopenia Virus (Cornell Feline Health Center)
- Hepatic Lipidosis (Fatty Liver Disease) in Cats (Veterinary Partner, VIN)
- Lily poisoning in cats (International Cat Care)
- CAPC General Guidelines (Companion Animal Parasite Council)
- Veterinary Exam and Procedure Costs (CareCredit)
This article is for general information and does not replace diagnosis or treatment by a veterinarian. If you are worried about your pet's health, call your vet clinic.
