Why Is My Cat’s Poop Watery? 8 Vet-Approved Reasons

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Last Updated on November 16, 2023 by Kit Copson

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	Dr. Tabitha Henson (Vet) Photo

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Dr. Tabitha Henson (Vet)

The information is current and up-to-date in accordance with the latest veterinarian research.

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Changes in the bathroom department are one of the biggest causes of worry amongst cat parents. Though diarrhea in cats isn’t the most unusual phenomenon, it’s important to figure out what may be causing it, especially if it’s regularly affecting your cat.

Watery poop can be caused by a range of situations and health conditions, and it can be difficult to pinpoint exactly what’s going on. If your cat is otherwise healthy and the diarrhea clears up on its own within 24 to 48 hours, it could just be a one-off. If the situation doesn’t improve, it’s time to have a chat with your vet to find out what’s up. For now, here are some potential causes of watery poop in cats.

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The 8 Likely Reasons for Watery Cat Poop

1. Dietary Changes

What may seem like a simple food change can cause havoc in your cat’s digestive system. Cats are incredibly sensitive to sudden changes in food, which can affect the balance in their intestines and cause diarrhea, vomiting, and lack of appetite.

It’s recommended to gradually introduce a new type of food to your cat by offering small amounts of the new food along with the current food. This allows you to gradually increase the amount you give them while phasing out the previous food.

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2. Food Allergies

Like humans, cats can also be allergic to certain foods—some cats are allergic to the meats commonly found in cat foods, like beef, fish, or poultry. Food allergies can also cause cats to become itchy, which leads to overgrooming to try and soothe themselves. Diarrhea and other gastrointestinal symptoms can also occur with food allergies.

3. Inflammatory Bowel Disease

Inflammatory Bowel Disease occurs when inflammatory cells attack the gastrointestinal wall, causing it to thicken and struggle to function properly as a result. In short, it is the chronic irritation and inflammation of the bowel or stomach and is caused by bacteria, parasites, or food allergies. Symptoms include chronic diarrhea and/or vomiting.

Cat vomiting
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4. Parasites

Gastrointestinal parasites are another condition that causes diarrhea in cats. Parasites can be worms or one-celled organisms and are transmitted by bites, eating spoiled meat, or infected feces. There are several different types of intestinal parasites.

These are:
  • Roundworms
  • Tapeworms
  • Hookworms
  • Whipworms
  • Giardia
  • Toxoplasma
  • Coccidia

Along with diarrhea, parasites can also cause bloodied or mucousy stools, vomiting, and bloating in some cases. Parasites are usually treated with medication prescribed by your vet.

5. Cat Exocrine Pancreatic Insufficiency

Cat Exocrine Pancreatic Insufficiency is a condition in which cats lack properly-functioning digestive enzymes to break down fats and proteins and produce insulin. It is caused by either pancreatitis, cancer, birth defects, or obstruction in some cases. Symptoms include watery diarrhea, lethargy, weight loss, and unformed feces.

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6. Cancer

Cancers of the gastrointestinal tract can sometimes cause diarrhea and vomiting. Though cancer is not as common in cats as it is in dogs, it tends to be more aggressive in cats. Feline Leukemia Virus (FeLV) can also cause persistent diarrhea.

Cancer can be especially difficult to spot in cats, as cats have a tendency to hide when they’re feeling unwell, even if they’re suffering from a serious illness. For this reason, it’s important to watch out for other signs as well as watery poop, which include:

  • A dull coat that looks more run-down than usual
  • Weight loss
  • Fever
  • Lumps that can be seen or felt through the skin
  • Breathing difficulties
  • Pale gums
  • Swollen lymph nodes
  • Seizures
  • Lethargy
  • Refusal to eat
  • Oral inflammation

7. Hyperthyroidism

Hyperthyroidism means that the thyroid gland is producing more thyroid hormones than is considered normal, causing the cat’s metabolism to speed up to abnormal levels. This condition most commonly occurs in cats over the age of eight. Diarrhea is but one of the symptoms, with others being a poor coat condition, hyperactivity, vomiting, weight loss, and frequent urination.

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8. Stress

Similar to humans, stress and anxiety can send a cat’s digestive system into a tailspin. Cats are highly sensitive in particular to changes, so if you’ve moved your furniture around, the smell in your home has changed, you’ve recently moved house or adopted a new cat, all of these things can contribute to your cat being stressed out. Even moving their litterbox can cause them to have jitters!

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What’s Considered Normal for Cat Poop?

A healthy cat bowel movement should be deep brown, not too hard or too soft, and not too foul-smelling. Of course, cat poop isn’t going to smell like a bouquet of roses, but you shouldn’t be heaving or running out of the room when you dispose of it, either!

On the other hand, abnormal cat poop is poop that is:
  • Black or tarry
  • Bloody
  • Contains mucus
  • Frothy
  • Greasy
  • Watery
  • Frothy
  • Hard and dry
  • Infrequent or too frequent

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Final Thoughts

Though watery cat poop isn’t uncommon, it isn’t normal either. This doesn’t mean that something serious is causing your cat’s diarrhea—causes can be minor or serious— but you certainly shouldn’t rule out health conditions, especially if the diarrhea doesn’t clear up on its own after a short time. If you’re worried about your cat’s bathroom habits for any reason, get in touch with your vet.

Featured Image Credit: topimages, Shutterstock

About the Author

Kit Copson
Kit Copson
Kit Copson is a freelance writer and lifelong animal lover with a strong interest in animal welfare. She has parented various furry beings over the years and is currently a proud cat mom of two—one very chilled (unless hungry) Siamese and a skittish but adorable Domestic Shorthair—and dog mom of one—an adopted Bichon Poodle cross. When not writing about or spending time with animals, Kit can be found doodling in her sketchpad, reading, or more often than not, drinking tea.

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