Choosing the Best Cat Food for Diarrhea [Written by a Vet]

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The trots. Hershey squirts. Mud butt. Excuse my potty humor, but we have to laugh or else we’d cry when our cats get chronic diarrhea, right? 

Cat diarrhea occurs when there is too much water in their poop. It’s usually due to changes in intestinal motility and/or inflammation in the intestines.

There are many causes, but in some cases, we never figure out just why it’s happening. It’s always worthwhile to consider the cat’s diet. But what is the best cat food for diarrhea? 

Finding the best cat food for diarrhea requires a process of trial and error to see what works. Veterinarians recommend comparing how your cat does on high fiber vs. low fiber cat food, novel protein vs. hydrolyzed protein vs. limited ingredient diets and dry vs. wet food. 

Recommended Cat Foods for Diarrhea

Criteria Used to Evaluate Cat Foods for Diarrhea

I’ve put together this guide to make the process a little less confusing for you. I’ve based the food choices on what veterinary nutritionists recommend as well as my own professional experience as a veterinarian.

  1. Complete and balanced nutrition from a trustworthy manufacturer
  2. Tastes good to most cats
  3. Convenience and affordability 
  4. Track record of success firming cat’s stool
  5. Include dry and wet food in the list
  6. Include high fiber and low fiber products in the list
  7. Include novel and hydrolyzed protein products in the list

Causes of Cat Diarrhea

There are so many possible causes of diarrhea in cats I can’t list them all. It’s important to consider age and lifestyle when trying to diagnose the cause of a cat’s diarrhea. 

Are they a newly adopted youngster or a senior cat who spends time with other cats outdoors? What is their health history? Are there any other symptoms like vomiting, weight loss or changes in hunger or thirst?

two cats sleeping (best cat food for diarrhea article)
The big “D” shouldn’t get in the way of friendship like this!

Here’s a short list of things I consider as causes of cat diarrhea. I like to check a fecal parasite test, a basic blood panel including thyroid levels and viral tests. Sometimes we’ll take x-rays and/or do some ultrasound imaging when we get further into our investigation. 

  • Intestinal parasites
  • Stress
  • Pancreatitis
  • Bacterial infection
  • Viral infection
  • Post-antibiotic diarrhea
  • Medication side-effect
  • Food intolerance
  • Food allergy (1)
  • Cancer
  • Hyperthyroidism
  • Liver disease
  • Kidney disease
  • Diabetes
  • Inflammatory bowel disease 

Treating Acute Diarrhea in Cats

Vets take a slightly different approach to diagnosing and treating acute diarrhea in cats. If a cat is otherwise healthy and has no health risk factors, your vet might not get super aggressive with testing. 

Many causes of acute diarrhea in otherwise healthy, indoor cats don’t require any treatment at all. Common causes include eating something gross and stress. You can feed a bland diet for a few days, but the most important factor is often time and patience. 

In other words, you don’t need to rush out and buy a 10-pound bag of special food. Nor should you start dosing your cat with anti-diarrhea medications made for humans!

If things aren’t improving after 2 to 3 days, consult your vet and start looking at the food choices discussed here. 

High Fiber Food: A Good Place to Start

It sure would be nice if all cats could get on the same page when it comes to dietary fiber. A high-fiber diet works great for some cats with diarrhea while it doesn’t help others or sometimes even makes the situation worse.

High-fiber cat foods usually contain both soluble and insoluble fiber. The insoluble fiber helps decrease the water content of the stool and firm it up. The soluble fiber feeds the good bacteria in the intestine which can also help get rid of diarrhea.

Blue Buffalo Wilderness High Protein Grain Free, Natural Adult Indoor

(Protein 36%, Fat 37%, Carb. 27%; Crude Fiber 7% Dry Matter)

Pros: Relatively lower in carbs for dry food at 27% of calories, higher in fiber at 7% dry matter, includes soluble fiber sources like peas and flaxseed, grain-free for sensitive cats, low cost and convenience of dry food. 

Cons: relatively lower cost, available at grocery and pet supply stores, etc.

Will your cat do well with high-fiber food? It’s hard to say without trying it, but you can evaluate your cat’s current food to see if it is of low or average fiber content. 

If the current food doesn’t have much fiber, consult your vet and ask if you should try the high-fiber food recommended above. Make sure you give the food at least a couple of weeks to see if it improves your cat’s bowel troubles.

If your cat is already eating high-fiber cat food, try low-fiber food to see if that improves his stool quality. Skip to the section on low-residue food below.

Speaking of Fiber–Does Pumpkin Firm Up Cat Stool?

Canned pumpkin seems to be the internet’s answer to all pet diarrhea! The idea is that the fiber in pumpkin is enough to stop a cat’s diarrhea. The truth is that while it has a moderate amount of fiber for natural food, it doesn’t have nearly as much fiber as high-fiber cat food. 

Low Fiber (Low Residue) Food

Low-residue is a term used especially on prescription diets. It means the food is highly digestible and the volume of feces produced by cats eating it is smaller. These foods usually have a lower fiber content along with high-quality protein. 

Purina ONE Sensitive Skin & Stomach

(Protein 34%, Fat 15%, Carb. 34%; Crude Fiber 2% Dry Matter)

Pros: low cost, the convenience of dry food, low/average fiber, moderate fat, no prescription necessary, widely available, cats like it.

Cons: highly processed, contains grains, low fat/high carbohydrate content.

Low-residue cat food works well for some but not all cats with diarrhea. Some examples of low-residue cat food include Hill’s ID food and Royal Canin’s gastrointestinal diet for cats.

Grain-Free Food

Grain-free cat food has been all the rage over the last ten or so years. I cannot point to any clinical studies that support the use of cat food made without grain. Still, some cats will get better when they are changed to grain-free food.

It’s true that as obligate carnivores, cats do not naturally eat grain. But most grain-free cat food simply switches out corn for peas or potatoes. Cats don’t naturally eat those foods either.

Natural Balance L.I.D. Limited Ingredient Diets Duck and Green Peas, Grain-Free

(Protein 30%, Fat 29%, Carb. 41%; Crude Fiber 4% Dry Matter)

Pros: grain-free, widely available, low cost compared to prescription diets.

Cons: not the gold standard for food allergy trials (may contain traces of other proteins), high in carbs at 41%, relatively high cost for non-prescription food, dry form, some cats might not like it. 

Some people believe eating grain causes inflammation. They apply this theory to humans, dogs, and cats. We need more scientific research into this topic before making large-scale recommendations to stop feeding grain to cats.

That said, it’s OK to make a gradual change to a high-quality, nutritionally balanced grain-free cat food to see if your cat’s diarrhea improves.  

It’s not unusual to see an improvement in feline chronic diarrhea with any change in a cat’s diet. But the improvement might be only temporary.

Is Wet or Dry Food Better for Cats with Diarrhea?

Many feline veterinary specialists feel that wet food works better than dry food for cats with diarrhea. This seems to be part of the general attitude that wet food is better for cats than dry cat food due to the moisture and lower carbohydrate content. 

Cats do not have a strong thirst drive and may exist in a state of chronic dehydration. Eating wet food may prevent this.

But this is mostly theory, there is mixed evidence on the topic of whether wet cat food is better than dry food for any given health condition.

Dry cat food is doctored up with flavor enhancers that seem addictive to some cats. Kitties scarf it down quickly only to vomit it up shortly afterward. If your cat does this, you might need to avoid dry cat food altogether. 

Personally, I have to wonder if wet cat food is easier for a cat’s stomach to break down than dry cat food. I think switching to wet cat food from dry cat food is worth a try to see if your cat’s diarrhea improves. 

Iams Grain Free Chicken Wet Cat Food

(Protein 39%, Fat 49%, Carb. 12%; Crude Fiber 5% Dry Matter)

Pros: grain-free, low/average fiber level 5% maximum of dry matter, low carb at 12% of metabolizable energy, non-prescription, simple ingredients–mostly chicken, wet food.

Cons: higher cost for an OTC product, not a good option if your kitty has issues with chicken.

But wet cat food is not the perfect solution for every domestic kitty. While it may be lower in carbohydrates than dry cat food, it’s usually significantly higher in fat than typical dry cat food. So you end up with a low-carb, high fat, moderate protein macronutrient ratio. 

Contrast that with a cat’s so-called ancestral diet which includes very little carbohydrate, relatively little fat and lots of protein. Feeding your cat high-fat food from a can is hardly approximating a wild cat’s diet of mice and birds.

Limited Ingredient Diet

A limited ingredient diet includes minimal nutrient sources in the hopes that eliminating certain ingredients will improve a cat’s litter box stool problems.

Although less specific than novel or hydrolyzed protein foods, limited ingredient cat food might help identify food a cat is sensitive to. It is important to use a prescription version of this special type of diet as over-the-counter products often have contamination with other ingredients from manufacturing.

Over-the-counter versions of limited ingredient diets that may work in cases of a mildly sensitive stomach. The prescription version of limited ingredient cat diets falls into the next category, novel protein cat food. 

Novel Protein Cat Food

Novel protein cat food uses a protein source that a cat has never been exposed to before. It’s best to use a prescription form of a novel protein diet because over-the-counter versions may have cross-contamination from other animal protein. Some of the common novel proteins used in this kind of food include duck and rabbit. Royal Canin, Purina and Hills all make veterinary-prescribed novel protein diets. 

Royal Canin Veterinary Diet Selected Protein Adult PD in Gel Canned

(Protein 31%, Fat 53%, Carb. 16%; Crude Fiber 11% Dry Matter)

Royal Canin Selected Protein PD canned cat food

Pros: low carb content at 16%, moist form but also available in dry, somewhat less processed than hydrolyzed diets, cats seem to like it.

Cons: peas are the first ingredient, high cost, prescription only.

Novel protein cat food works on the principle that a cat’s body is reacting negatively to the protein source in the food. By taking away that irritating protein source, the intestinal tissue will calm down and diarrhea should resolve. 

It can take two to three months to see the full effects of a novel protein diet. During that time, you must not give your cat any other food sources. 

If a cat owner continues giving their cat various treats, they’ll never know if the food is improving things or not. 

Hydrolyzed Protein Cat Food

Royal Canin Ultamino Dry Cat Food

(Protein 23%, Fat 35%, Carb. 42%; Crude Fiber 6% Dry Matter)

Royal Canin Ultamino Cat Food

Pros: many vets consider this the gold standard for food allergy trials, works well for food allergy.

Cons: highest cost among the hydrolyzed dry diets I reviewed, prescription only, dry form only, some cats might not like it. 

Hydrolyzed protein diets work miraculously well for many pets, but they’re only available by prescription. And they’re pretty expensive compared to grocery store food. Finally, some people don’t like them because they think they’re too unnatural.

Does Fat Content of Cat Food Matter?

A 2012 study looked at 60 cats with chronic diarrhea and fed them either high or low-fat cat food. Many cats improved during the trial but it didn’t seem to matter how much fat was in their food. (2) Cats have a much higher tolerance for fat than dogs do! 

Conclusion: you don’t necessarily need to feed low-fat food to your cat with chronic diarrhea. 

Should You Choose Food with Probiotics?

The jury is out on whether probiotics included in cat food can have a positive effect on healthy digestion. Many vets doubt that the concentration of probiotic organisms is high enough or stable enough to work as well as a separate probiotic supplement. (3) 

My opinion? If your cat has a sensitive stomach and/or diarrhea and you want to use a probiotic, use a separate supplement until he’s back to normal. I like Proviable DC for cats, but Fortiflora is also good and picky eaters seem to love its flavor. 

After that, a diet containing probiotics might help prevent a recurrence of diarrhea in the litter box. I recommend a prescription food if you can swing it: Hill’s Prescription Diet Gastrointestinal Biome Digestive/Fiber Care Cat Food.

Speaking of Probiotics–Is Yogurt Good for Cats with Diarrhea?

Most yogurt contains live beneficial bacteria that may have a beneficial effect on a cat’s digestive health. However, the amount is much less than what your cat would get in a decent probiotic supplement. Plus yogurt is made from cow’s milk which many cats don’t digest well. 

I recommend using a separate probiotic supplement like Proviable DC. 

When Changing Food Isn’t Enough

What if you’ve tried all the strategies I’ve mentioned and your cat still has a sensitive stomach and diarrhea? It’s time to do some diagnostic testing including blood tests, fecal tests and x-rays. 

But your vet might go through all of the reasonable diagnostic tests without pinpointing a cause for a cat’s chronic diarrhea. 

We are left with the choice of doing biopsies of the gi tract or doing a medicine trial with antibiotics, anti-inflammatory and/or immune-suppressive drugs. Some cats improve with this empirical therapy and can get along with fewer drugs after a time. 

Summary

There is no one best cat food for diarrhea and a sensitive stomach but there is a systematic approach to finding out which works best for your unique cat. Most vets recommend experimenting with 

  • Fiber levels
  • Protein sources
  • Dry and wet food forms

Remember to change from the old food to the new food gradually over 7-10 days and continue on the new food at least a few weeks before drawing a conclusion. Your veterinarian can help you put together a plan and interpret the results. 

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References

  1. Guilford, W. G., Markwell, P. J., Jones, B. R., Harte, J. G., & Wills, J. M. (1998). Prevalence and causes of food sensitivity in cats with chronic pruritus, vomiting or diarrhea. The Journal of nutrition, 128(12), 2790S-2791S.
  2. Laflamme, D. P., Xu, H., & Long, G. M. (2011). Effect of diets differing in fat content on chronic diarrhea in cats. Journal of veterinary internal medicine, 25(2), 230-235.
  3. Weese, J. S., & Arroyo, L. (2003). Bacteriological evaluation of dog and cat diets that claim to contain probiotics. The Canadian veterinary journal, 44(3), 212.

Last update on 2023-03-29 / Affiliate links / Images from Amazon Product Advertising API