How Important Fiber & Fat is to an EPI Dog?

For dogs with Exocrine Pancreatic Insufficiency (EPI), the recommended guidelines (on a dry matter basis) are a maximum crude fiber content of 4-5% and a moderate fat content typically between 10% and 15%. All dogs are different though. You will need to work out what is best for your dog.

Fiber & EPI — Simple Guide for Pet Owners

This guide explains, in clear and practical terms, how different types of fiber affect dogs and cats with Exocrine Pancreatic Insufficiency (EPI). The goal is to help you understand why food choices matter so much and how fiber can either help or interfere with your pet’s EPI treatment.

1. Basic idea

Dogs and cats have short digestive tracts and are designed to digest mostly meat. Many commercial pet foods include plants (grains or vegetables) that add carbohydrates and fiber. For most healthy pets this is fine. But for EPI pets, some types of fiber can make digestion harder.

The good news: once you understand how fiber works, choosing the right diet becomes much easier.

2. Why fiber matters in EPI

2.1 It can weaken enzyme effectiveness

EPI pets must take pancreatic enzyme replacement. Some types of fiber can bind to the enzymes or block them, making them work much less effectively. In some cases this can cut enzyme function by up to half, causing:

  • loose or messy stools
  • poor weight gain
  • ongoing digestion issues

2.2 It can reduce nutrient absorption

Too much fiber or the wrong type of fiber can:

  • speed food through the gut too quickly
  • thicken the food too much for enzymes to mix properly
  • make it harder for the body to absorb nutrients (especially fats)

2.3 It affects gut bacteria

Some fibers are fermentable — this means gut bacteria break them down into gases and short-chain fatty acids (SCFAs). These can help or harm. In EPI pets, too much fermentation can lead to SID/SIBO (overgrowth of bacteria), causing:

  • gas
  • bloating
  • diarrhea
  • unpredictable stools

3. Types of fiber and what they do

3.1 Soluble, fermentable fiber

Examples: beet pulp, some fruit fibers, certain plant gums.

  • Turns gel-like in the gut
  • Feeds good bacteria
  • Can help stool quality in small amounts
  • But too much can cause gas and loose stools in EPI pets

3.2 Insoluble fiber

Examples: wheat bran, cellulose.

  • Adds bulk to the stool
  • Speeds food movement through the gut
  • Often not tolerated well by EPI pets

3.3 Viscous (thickening) fibers

Examples: gums, pectins.

  • Can make food thick and harder for enzymes to mix with
  • Often reduces enzyme effectiveness

3.4 Prebiotic fibers

Examples: FOS, inulin.

  • Feed helpful gut bacteria
  • Can be useful in small doses when advised by a vet
  • But can worsen symptoms if the pet has SID/SIBO

4. Grains vs. vegetables — what’s the difference?

Grains and vegetables both have carbohydrates and fiber, but the type of fiber differs.

  • Grain bran (husk) = usually harsh, bulky fiber. Often a problem for EPI pets.
  • Cooked grains (like well-cooked white rice) = easier to digest; many EPI pets tolerate them.
  • Vegetable fibers vary. For example:
    • Cooked pumpkin: often helpful in small amounts.
    • Peas/legumes: more fermentable → can cause gas.

This explains why some EPI pets tolerate certain foods while others do not.

5. Why EPI pets react differently to the same food

Every EPI pet has their own “gut picture.” Differences come from:

  • their individual microbiome
  • how severe their EPI is
  • how well enzymes are dosed
  • whether they have SID/SIBO
  • how the food is processed (cooked vs whole grain)

So two pets can eat the same food — one does great, the other does poorly.

6. SCFAs and what they mean

When bacteria ferment fiber, they make short-chain fatty acids (SCFAs). These can help the large intestine stay healthy. But too much fermentation in the small intestine can:

  • cause gas and bloating
  • upset digestion
  • worsen nutrient absorption

This is why the type and amount of fiber matter.

7. Simple feeding guidelines for EPI pets

  1. Choose low-fiber foods when possible.
  2. Use highly digestible, animal‑based diets.
  3. Pick gentle carbs like cooked white rice or cooked potatoes (if tolerated).
  4. Avoid high-bran, high-cellulose, or thickening fibers.
  5. Introduce diet changes slowly.
  6. Watch stool, weight, appetite, and gas.
  7. Work with your vet to adjust enzymes or treat SID/SIBO.

8. When a prebiotic might help

A prebiotic may be useful if:

  • stool remains loose even when enzymes and diet seem correct
  • your vet suspects the gut bacteria are unbalanced

But it must be done carefully, because adding the wrong type or amount can worsen symptoms.

9. Troubleshooting

  • Loose stools? Check fiber type and enzyme dose.
  • Gas or bloating? Reduce fermentable fiber and talk to your vet about possible SID/SIBO.
  • Weight loss? Recheck enzyme dosing and the digestibility of the food.

10. Why Low Fat Is Also Important for EPI Pets

Many EPI dogs and cats struggle to digest fat, even when they are receiving pancreatic enzymes. Fat digestion relies heavily on pancreatic lipase—an enzyme EPI pets cannot produce enough of. This means:

10.1 Undigested fat leads to classic EPI symptoms

If dietary fat isn’t broken down properly, it passes through the intestines undigested, causing:

  • pale, greasy, or shiny stools
  • diarrhea
  • weight loss despite a good appetite
  • gas and abdominal discomfort

This is why lowering fat—at least during the early stages of treatment—often helps stabilize stools.

10.2 High fat needs higher enzyme doses

Fat digestion requires more enzyme power than protein or carbohydrates. The higher the fat in the diet, the more enzymes are needed. Some pets can tolerate moderate-fat diets once stabilized, but many cannot.

10.3 Fat can worsen SID/SIBO if not digested properly

When fat stays undigested:

  • bacteria in the small intestine feed on it
  • this encourages overgrowth (SID/SIBO)
  • which makes digestion even worse

This becomes a cycle: poor fat digestion → dysbiosis → worse digestion → worse symptoms.

10.4 Low-to-moderate fat makes enzyme therapy easier

Feeding a lower-fat diet helps:

  • enzymes work more effectively
  • stools firm up more consistently
  • the gut calm down
  • the pet gain weight more steadily

Some EPI pets can eventually increase fat once stable. Others remain sensitive and do best long‑term with controlled fat levels.

11. Bottom line

Choosing the right fiber — and the right amount — can dramatically improve EPI management. Diet is often the final key to stabilizing an EPI dog or cat. Paying attention to fiber type, cooking method, enzyme use, and gut health can make a major difference in your pet’s quality of life.