Causes of Cat Diarrhea

Caymus doing his duty in the NVR Miss Litter Box (two are stacked together here)

As when it appears in humans, diarrhea in cats can be alarming and deserves immediate attention. Below are a few causes of cat diarrhea, steps you should take when your cat has diarrhea, and some treatments and prevention strategies.

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There are several possible reasons for cat diarrhea, some more serious than others:

  • Diet – changes in diet, dairy or food intolerance, spoiled food, or allergies to food
  • Parasites – roundworms, Giardia, coccidia, etc.
  • Infection – viral or bacterial
  • Disease – i.e., kidney, liver, inflammatory bowel, hyperthyroidism
  • Some medications – i.e., antibiotics combined with probiotics can cause a reaction
  • Cancer or tumors
  • Colitis

These are some of the more severe causes of diarrhea that might require medication. Still, diarrhea could also be caused by small household dangers that you might be overlooking, for example:

  • Plants – many plants with bulbs are dangerous to cats
  • Flea treatment or flea collar
  • Household chemicals – laundry detergent, cleaners, soaps
  • Air fresheners
  • Pesticides
  • New water bowls, food bowls, or toys
  • Algae buildup in water bowls
  • Changes in cat litter

Determining the cause of your cat’s diarrhea is half the battle of treating it. Always consult a vet first when dealing with cat diarrhea, but be ready to do some detective work in case the cause is in your home.

What to Do When Your Cat Has Diarrhea

Call the Vet

If diarrhea lasts for more than a day, you should first call your veterinarian and be ready to give a detailed description of symptoms and timeline. Here are some questions your vet might ask you to help determine the cause of diarrhea:

  • When did the diarrhea start, and how many bowel movements has your cat had?
  • Does your cat appear to be in pain?
  • Are the stools bloody, black, or tarry?
  • Is your cat exhibiting other symptoms like fever, vomiting, lethargy, or dehydration?
  • Is it possible that your cat ingested something poisonous?
  • Are your cat’s gums yellow or pale?
  • Are your cat’s vaccinations up to date?

If your cat is experiencing diarrhea, be ready to provide the vet with these answers when you call.

Go to the Vet

The next step after calling your vet might be to make an appointment for further tests – note that if there is blood in your cat’s stool or they are exhibiting other severe symptoms, you should take them to the vet immediately. The vet will take several steps to determine the cause and the best treatment for your kitty, including:

  • asking you for details about your cat’s symptoms and medical history
  • a physical exam
  • a stool test

If this first round still doesn’t lead to a diagnosis, vets will use other testing methods, including:

  • testing for parasites or bacterial infections
  • blood tests
  • x-rays
  • ultrasounds
  • colonoscopy

When you take your cat to the vet, be prepared to provide them with as much information as possible about symptoms, medical history, and any potential sources of poisoning around your house. Do not give your pet any human medicines unless specifically instructed by the vet.

Look for the Cause at Home

If your vet rules out serious diseases or infections, but diarrhea persists, it’s time to start looking around your home for the culprit.

First, consider the list of household substances above that could cause diarrhea. Next, try to rid your home of toxic chemicals your cat might be exposed to – plug-in air fresheners, pesticides, harmful plants, and other things close to the ground or within their reach.

Changes in your cat’s food and environment might also be the cause. For example, some cats experience diarrhea after a change in food brand, a move to a new city where food or water quality might be different, or dairy in their diet.

In addition, a change in the litter can be problematic if your cat is licking the residue off their paws and ingesting the litter. Other changes that could introduce something toxic include new food or water bowls or new toys.

One possible action is to “quarantine” your cat in a room with their food, water, and a litter box for a few days, sticking to basic food only. Then, if diarrhea stops, you know that it was caused by something your cat was getting into, and you can slowly reintroduce treats, toys, and areas of the house to try and determine the cause by elimination.

Treatments & Prevention

Once you have determined the cause, your vet can recommend a course of treatment. Some common treatments include the following:

  • temporarily withholding food
  • diet change – temporary or permanent
  • IV fluids for dehydration
  • antibiotics
  • wormers
  • other medications

Some pet owners also recommend the home remedy of mixing a little pumpkin into wet food.

To prevent diarrhea, do a safety check of your house to ensure your pet isn’t coming into contact with dangerous plants, chemicals, or other toxic household substances. In addition, to help prevent food-related diarrhea when switching foods, veterinarians recommend slowly mixing the new food in with the old to avoid shocking your cat’s digestive system.

Cat diarrhea can occur for many reasons, and your vet should be your go-to source of information if it appears. But remember that you can protect your pets from many possible causes of diarrhea by ensuring that your household is free of toxic substances that could mess with a cat’s digestive system.

What are the reasons your cat has experienced diarrhea? What course of treatment worked? What toxic household substances or items do you avoid? Let us know!

In my home, if I know I haven’t added anything crazy new or different and the cats haven’t been exposed to something else, I usually try feline probiotics on them to see if that will get rid of diarrhea. They work 99% of the time.


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Hi, I’m Jenny Dean, creator of Floppycats! Ever since my Aunt got the first Ragdoll cat in our family, I have loved the breed. Inspired by my childhood Ragdoll cat, Rags, I created Floppycats to connect, share and inspire other Ragdoll cat lovers around the world,

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  1. Christina says:

    Thanks for this post. Another tidbit I’d share I learned recently with Sir Quimby’s kitten loose bad smelling stools (I even contacted you on it). Is immunization – they use chicken or beef ovum to grow the agents they inject into your kitten. It is believed that this may be the cause of some sort chicken or beef intolerance during immunization. Quimby had a terrible chicken intolerance that caused me to notice just how much chicken is used in cat food, even if it says salmon, the first and second ingredients can be chicken.
    We found Fromm three stars grain free beef and rabbit/duck had the small enough kibble and the tunachovy he could tolerate later.
    Only a share.
    Our breeder didn’t really emphasize one cat food and told me grain free and told me three or four different types. She also felt that any Fromm flavor was equal to their kitten brand. Same with my previous breeder for Sebastian who said to feed him Royal canine bit no specific flavor. Breeders can be eccentric in their ways too :).
    If someone already mentioned the immunization and intolerance in am earlier post, apologies – I missed it in my reading

  2. Amy Cirillo says:

    Wow, you posted this just as our kitty Fede started having loose stools. Thanks!! How long does it usually take the probiotics to work, in your experience? My vet recommended Culturelle for humans, and I sprinkle 1/4-1/2 the contents of a pill onto the food and then mix it in. Fede’s stool sample was negative, and the diarrhea got a little worse, so the vert recommended a bland diet of rice and boiled chicken. Thanks!

    1. It usually takes a few days for us…one time with Charlie it was bad for a week or so. I had to force him to eat pumpkin mixed with wet food.

      1. Wayne Robinson says:

        Weruva “Funk in the Trunk” contains pumpkin. Good to keep on hand.

  3. Wayne Robinson says:

    Well timed, Jenny! I’m having this problem with Loki right now. He turned five months old today! But last week he started having very loose stools several times a day. He’s perfectly fine in every other respect. I put it down to the Canidae grain-free dry food I introduced him to the day before. I’m not a dry food fan as you know(!), but I like him to be familiar with it, so he only gets it as a snack.
    I’ve been wracking my brain to figure out why the Canidae might be the cause, as I’m fully confident that it’s a great product and Loki is used to a huge variety of food. He gets fed a rotation of ZiwiPeak, Wellness (CORE and regular varieties) and Weruva Cats in the Kitchen as well as Whole Life treats and fresh chicken wings and lamb cutlets.
    The dry food I normally give him is Black Hawk grain-free, an Australian brand with excellent ingredients and really large triangular crunchy kibble which the cats have to actually CHEW and not simply hoover up, like most other dry food. I’m really impressed with it and Loki loves it. So Black Hawk *might* actually be good for their teeth. He simply REFUSES to eat the Wellness CORE dry kitten formula which I bought him originally.
    Anyway, my point is, Loki eats a large variety of food with no problems at all, even when I introduce new varieties. Until Canidae. Now, here’s the clanger: Canidae sprays the kibble after it’s cooked with their own proprietary blend of probiotics and I reckon THAT must be what’s caused his mild diarrhea. I stopped feeding him it and a few days later, the problem went away. I then gave him a little and the problem came back! It’s got to be the probiotics. So I’ve decided to take the risk and continue to feed him a little of it each day to see if he adjusts. I’ll monitor him closely and if it doesn’t go way, then it’s good bye Canidae. Which would be a shame because I really respect the company and their philosophy and I’d love to have it in his ‘rotation’.
    I always thought probiotics were *good* for diarrhea, and still do. But, as we do, I got online and researched it and, yes, in some cases it can give them diarrhea until their little bellies adjust. I also ordered some probiotics (PAW Digesticare 60) online to have on hand. FortFlora is not available over here.
    Fingers crossed that he adjusts. He’s a magnificent little boy and he’s growing so fast!

    1. AH – yes, I gave Charlie and Trigg a different probiotic one time when they weren’t having loose stools and it created loose stool! Please keep us up-to-date on how Loki does!

      1. Wayne Robinson says:

        Well, he only did one yesterday. That’s a good sign. He’s been doing 3-4 a day. The little bugger has decided he’d rather poo in the garden in the enclosed courtyard out the back where he loves to get outside and play, which makes it hard to monitor him. This morning I was determined not to let him out so I could check his litter box, but he escaped! Needless to say he ran straight to the garden ad did one! Still loose but seems a bit better. I’m still going to keep giving him a little of the Canidae each day and hope he adjusts.

        Only true cat lovers could have this conversation LOL

    2. Christina says:

      Hello Wayne
      Please check out my post below about my experience with loose stools and immunization with my RD kitten

      Also, I have learned that Pumpkin helps. Just 10% of the food with canned pumpkin added for a few days max. It supposed to clear up bowel irregularities. I found it worked better with constipation but it does help with loose stools. Google it up 🙂
      Good luck to you and Loki. Sir Quimby had similar issue and it was a chicken intolerance

      1. Wayne Robinson says:

        Thanks, Christina. Some good advice there! I know it’s not an intolerance to a particular meat because Loki gets everything: chicken, turkey, rabbit, lamb, beef, fish, venison, even New Zealand green-lipped mussels in the ZiwiPeak. And he was immunized at 12 weeks. I’m pretty sure it’s the probiotics in the Canidae GF dry. He’s been getting some pumpkin too that comes in the Weruva Funk in the Trunk. He seems to have settled down a bit over yesterday and today, but he’s often surrounded by a faint cloud of fart, especially when he’s relaxed and getting a belly rub! LOL

        1. Christina says:

          Ha ha – yep kitten farts are dangerous
          We tried live probiotics (the kind humans get refrigerated) but Quimby wouldn’t eat it.
          Good luck.

          We found luck with Instinctive brand rabbit a d raw rabbit. (It’s only coated with raw freeze dried meat)
          No more gas or loose stools

    3. Christina says:

      Psst…one more thing Wayne. While I was resting Quimbys tummy I used baby food. This helped me pinpoint the exact meat intolerance too. Beef or Pork baby food helped. Chicken caused the trots. I only give it for a meal or two, but when their bowels are angry, something mellow like baby food helps and Moms make sure it’s made healthy or the baby food company s would be burned to the ground (joking)

  4. Thank you so much for this very wonderful post, Jenny! I actually learned quite a bit and will have this bookmarked for future reference should I ever need to refer it. So far, we’ve been very fortunate with Miss Pink Sugarbelle. She’s not had any diarrhea issues. Yay!

    Big hugs!

    Patti & Miss Pink Sugarbelle 🙂 <3

    1. Good deal, thanks, Patti – btw, I noticed the newer profile photo! Man, you don’t have a wrinkle on your face – impressive!

      1. Thanks! lol…I’ve got plenty or wrinkles (crinkles) around my eyes but the picture hides them well…lol I’m only 56 but so far I’ve been pretty lucky with the wrinkles and facial lines. I’m sure it will all catch up to me sooner or later… 🙂 <3

  5. Lyn Johnson says:

    I’m getting a new kitten in a few weeks. I’m so worried I’m going to do something wrong. The breeder uses Tidy Cat Light cat litter (I’ve read bad reviews for this litter), and I used Dr Elsey’s Precious Cat litter for a previous cat I had (I like that litter, and I still have 2 18-lb unopened bags). In addition, the breeder uses Royal Canin Feline Health Kitten Chaton (dry food). I don’t want to change things out too soon for a kitten that’s accustomed to this litter and dry food. How would you recommend I change the litter and food out? I certainly don’t want her to get diarrhea.

    1. Hi Lyn, are you familiar with my book, A Ragdoll Kitten Care Guide: Bringing Your Ragdoll Kitten Home, it explains about these types of isses. For best results, you want to buy small bags of the products your kitten is already on (because she will be familiar with them and her whole world will be turned upside down from what she’s known, so best to have familiar products around)…and then after the kitten is comfortable and feeling safe in your home (usually about 2 weeks after being there), then you can slowly transition her to the products you’d like to use.

      This is a great site for cat info and here’s a great article on how to transition kitties to a new cat litter.

      And this post talks about transitioning food – diarrhea is always a concern, especially if she comes spayed because she will have had antibiotics which get rid of her good bacteria in her tummy – so you might need a course of probiotics. There is a lot of great information about cat nutrition on this site, run by a vet.

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