Is Your Cat's Diarrhea a Cause for Concern?

Analysis by Dr. Karen Shaw Becker

feline diarrhea

Story at-a-glance -

  • When cats have diarrhea, it typically involves either the small or large bowel; occasionally, it can involve both
  • There are many causes of diarrhea — very often, a rapid transition to a new diet is the trigger; however, some causes are very serious, so it’s important to have repeated episodes checked out by your veterinarian
  • To improve your kitty’s digestive function and overall health, it’s best to vary her diet rather than feed the same food day in and day out
  • To treat a temporary episode of diarrhea at home, I recommend a short-term fast followed by a bland diet of cooked, fat-free turkey and 100% canned pumpkin

Generally speaking, when it comes to digestive upsets in pets, dogs tend to have lower gastrointestinal (GI) symptoms and diarrhea, while cats are more prone to upper GI tract issues and vomiting. However, as anyone who has ever scooped unformed poop from a litterbox can attest — kitties can and do develop diarrhea sometimes.

Types of Diarrhea in Cats

When veterinarians set out to diagnose a feline patient with diarrhea, they generally put the problem into one of two categories based on where in the intestinal tract the loose stool is originating — either the small bowel or the large bowel.

If the problem is with the small bowel, the diarrhea is often large in volume, watery, and occurs with increased frequency. When a kitty’s diarrhea originates in the large bowel, it will more typically be small in volume, semi-formed, and may contain mucus. There’s often also increased frequency and straining to go.

Some feline diseases with diarrhea as a symptom involve both the small and large bowel, and in addition, a cat can start out with small bowel diarrhea that subsequently causes secondary irritation of the large bowel.

Blood in the stool can be a feature of both types of diarrhea. Dark, tarry stools indicate the presence of digested blood from the stomach or small intestine. Fresh streaks of blood in or on the stool are usually a sign of a large bowel problem. Vomiting along with diarrhea is more often seen in diseases of the small bowel but can also occur with a large bowel problem.

Causes of Diarrhea

The causes of loose stools in cats are numerous and varied, and include:

Dietary indiscretion; ingestion of foreign bodies

Inflammatory bowel disease (IBD)

Pancreatitis

Sudden change in diet

Giardia and other parasites

Immune-mediated disease

Food allergies

Viral and bacterial infections

Megacolon

Stress colitis

Hyperthyroidism

Cancer

If your cat has a one-and-done bout of loose stools that resolves within a day or two, chances are she ate something that disagreed with her (or you gave her milk, which is a common culprit in feline digestive issues) and there’s nothing to worry about.

However, since there are many serious feline diseases that have diarrhea as a symptom, if your kitty is experiencing chronic or recurrent diarrhea, it’s time to make an appointment with your veterinarian.

Dehydration is an immediate and potentially life-threatening concern, especially for kittens, petite adult cats, and kitties who are seniors or geriatric, or have a chronic illness. Also, if the diarrhea is accompanied by other signs of illness such as blood in the stool, vomiting, loss of appetite, and/or fever, it’s definitely a sign your pet is ill, and you should seek veterinary care.

I recommend you collect a quarter-size bit of poop on, for example, a stiff piece of cardboard, and slip it into a plastic baggie. Otherwise, your veterinarian may have to manually extract a sample, which will make your already uncomfortable kitty that much more so.

Your vet will probably do bloodwork in addition to evaluating the stool to determine if there's infection present. He or she should also treat your pet for dehydration if necessary, with IV (intravenous) or SQ (subcutaneous) fluids.

Two fecal tests should be performed. One checks for parasite antigens and/or eggs, and the other checks for bacterial or viral agents that cause diarrhea.

A Too-Fast Dietary Change Is Often the Culprit

In otherwise healthy cats, often it’s a sudden change in diet that triggers a bout of diarrhea, and this is especially true for kitties who eat the same food every day. If you feed your cat the same diet every day for months or years and then suddenly switch to a new food, a case of diarrhea is almost guaranteed.

There’s nothing wrong with the new food, it’s just that kitty’s gut is conditioned to expect only one type of food, which is not ideal, nutritionally or physiologically. Cats fed a varied diet have stronger, more resilient GI tracts and can typically eat different foods regularly without a problem.

After your pet’s stools have returned to normal (I’ll discuss treating diarrhea at home shortly), I recommend you begin varying his diet to include a range of foods with different nutrient contents. This will promote a diversified gut microbiome and make his digestive system strong and resilient.

However, you need to make the transition very slowly, as in, over a period of weeks to months. I recommend starting with 10% new food blended with 90% old food for several days. Watch your cat's stool and if all seems well, move to 20% new/80% old. Keep watching for stool changes and if none occur, move to 30% new food and 70% old, and so on, until you're feeding only the new diet.

The process should be slow enough that no bowel changes occur. During the transition period, it’s very important to insure your kitty is eating every day, as cats can’t go without food for long or they risk developing fatty liver disease.

For tips on how to make the transition (especially if kitty is giving you a hard time about the new food), take a look at my videos titled Getting Your Cat to Eat Healthier Food, part 1 and part 2.

Treating Diarrhea at Home

If your cat is otherwise healthy and his behavior is normal, my recommendation is to withhold food — not water, just food — for 12 hours. A short-term fast gives the GI tract a chance for some R&R. Tissues can only heal when they're resting.

Follow the 12-hour food fast with a bland diet. I recommend cooked, fat-free ground turkey and 100% canned pumpkin. Try starting with an 85-90% turkey/10-15% pumpkin blend. If canned pumpkin isn't available, you can use fresh, steamed pumpkin or cooked sweet potato. This diet can also be pureed and syringe-fed to kitties that may not feel like eating.

Skip the outdated advice to feed ground beef and rice and go with my recommendation instead. Even lean ground beef is high in fat, which can exacerbate kitty’s tummy troubles, and rice is a starchy, pro-inflammatory carbohydrate that often provides zero nutrition or calories for animals with digestive issues.

Canned 100% pumpkin provides about 80 calories and 7 grams of soluble fiber per cup, compared to 1.2 grams of fiber in a cup of cooked white rice. The soluble fiber in pumpkin coats and soothes the GI tract, and also delays gastric emptying.

When animals have diarrhea, they can lose important electrolytes, including potassium, which puts them at risk of dehydration. Hypokalemia, or low potassium levels, can result in cramping, fatigue, weakness and heart rate irregularities.

Pumpkin happens to be an excellent source of potassium, with 505 milligrams of naturally occurring potassium per cup. Pumpkin is also safer for diabetic pets than rice. And most animals love it, including cats. Feed the bland diet to your pet until the diarrhea resolves. If it doesn't clear up in about three days, it's time to call your veterinarian. If at any point your cat becomes lethargic or anorexic, seek medical care immediately.

I also recommend keeping some slippery elm on hand. Slippery elm is a neutral fiber source that works really well to ease episodes of diarrhea. I call it "nature's Pepto-Bismol" because it reduces GI inflammation and acts as a non-irritating source of fiber to bulk up the stool and slow down GI transit time.

Give your cat about a half a teaspoon or a capsule for each 10 pounds of body weight with every bland meal. I also recommend adding in a good-quality probiotic once the stool starts to firm up.

In addition to slippery elm and probiotics, many pet owners have good luck with herbs such as peppermint, fennel or chamomile. These are especially helpful for the cramping and other uncomfortable GI symptoms that come with diarrhea. Activated charcoal can also help firm the stool if dietary indiscretion is suspected.

There are also several homeopathic remedies that can be very beneficial for intermittent diarrhea depending on your pet's specific symptoms, including nux vomica, veratrum, podophyllum, arsenicum album and china.

+ Sources and References