Exocrine pancreatic insufficiency (EPI) means the pancreas can't make enough digestive enzymes, so food passes through the gut largely undigested. Affected dogs lose weight even though they're often ravenously hungry, and they pass large amounts of pale, soft, greasy stool.1,2 A simple fasting blood test (cTLI) confirms it.3,1 EPI is usually lifelong, but with powdered pancreatic enzymes in every meal and vitamin B12 if needed, most dogs gain weight quickly and can live a normal life span.1,4
See your vet promptly if your dog:
- Is losing weight despite eating well or more than usual1,2
- Has large, pale, loose or greasy stools for more than a few days1,5
- Has EPI and starts vomiting, stops eating or gets bloody stool, which may mean another problem1
- Has EPI and is drinking and urinating much more, which can mean diabetes when EPI follows chronic pancreatitis4,2
What the Research Says
- Signs appear late. About 90% of the enzyme-producing tissue has to be lost before a dog shows signs.1,5
- The stool tells the story. In 109 German Shepherds with EPI, 99% had grey or yellowish stools, 95% passed large amounts, 90% went more than three times a day and 61% ate stool.5
- Most dogs do well. In a study of 178 dogs, 60% responded fully to treatment, 17% partly and 23% poorly. Treated dogs lived a median of about 5 years after diagnosis.6
- Vitamin B12 matters. Most dogs with EPI have low B12, and very low B12 was linked to shorter survival.6,3,1
- Strict low-fat diets don't help. In 21 dogs with EPI, a very low-fat diet gave no significant benefit, and in 116 dogs, special diets didn't improve survival.5,6
Signs of EPI in Dogs
- Weight loss, often marked, even though the dog eats normally or more.1,2
- A big appetite; many dogs seem constantly hungry.1,5
- Large amounts of pale, soft stool, often yellow or grey, greasy-looking and smelly, passed more than three times a day.1,5,4 Watery diarrhea is uncommon.1
- Eating stool or other non-food items, lots of gas and loud gut noises.5,4
- A poor, greasy or dull coat, sometimes oily fur around the tail, and muscle loss.2,4
Vomiting and poor appetite are less typical and may point to another condition alongside EPI.1 Many owners at first think their dog is simply greedy. Compare stools with our dog poop chart.
Causes and Breeds
| Cause | Typical dogs | Notes |
|---|---|---|
| Pancreatic acinar atrophy (the enzyme-making cells waste away) | Young adult German Shepherds, Rough Collies, Eurasiers; Chow Chows often diagnosed young1,7 | The most common cause in these breeds; an immune attack on the gland is suspected4 |
| Chronic pancreatitis (long-term inflammation that scars the gland) | Middle-aged and older dogs of any breed; Cavalier King Charles Spaniels often diagnosed later in life1,7 | The most common cause in other breeds; can come with diabetes1,4 |
| Rare causes | Any dog | A mass blocking the pancreatic duct, or cancer near the pancreas1,2 |
In a study of more than 13,000 lab tests, Chow Chows, Cavalier King Charles Spaniels, Rough Collies and German Shepherds were overrepresented, while Boxers, Golden Retrievers and Labradors were less often affected.7 Other breeds reported include Cairn and West Highland White Terriers, Cocker Spaniels and Border Collies.2,8
Is it inherited? Acinar atrophy runs in German Shepherd families. Early pedigree studies pointed to a single recessive gene, but later breeding work didn't support a simple pattern, and no gene has been found.9,10,8,4 Dogs with acinar atrophy shouldn't be bred.4 See pancreatitis in dogs.
How Vets Test for EPI
The key test is serum trypsin-like immunoreactivity (cTLI), a blood test taken after 8 to 12 hours without food.3,1 Vitamin B12 (cobalamin) and folate are measured at the same time.3
| cTLI result (µg/L) | What it means |
|---|---|
| 5.5 or lower | Confirms EPI3,11 |
| 5.6 to 7.5 | Grey zone; EPI not ruled out. Retest in 1 to 2 months, or try enzymes if signs fit3,11 |
| 7.6 to 10.8 | EPI unlikely3,11 |
| 10.9 or higher | Normal3 |
These cutoffs are from the Texas A&M Gastrointestinal Laboratory, which revised its normal range in 2024; your lab's report may differ slightly.3 Stool enzyme tests are much less reliable.1 Some German Shepherds have a very low cTLI with no or only occasional signs.1
Treatment
- Pancreatic enzyme replacement with every meal. This is the mainstay. Powders work better than tablets or capsules. Raw pancreas from a butcher can substitute, but avoid game animals, which can carry a dangerous tapeworm.1,4 Your vet will set the amount, and many dogs can later get by on less once they're doing well.5,8
- Vitamin B12 (cobalamin) injections or tablets if levels are low. Enzymes alone don't fix B12 deficiency.1,5,12
- Diet: a good-quality, highly digestible food that is low in fiber, with normal (not reduced) fat.1,8,5 Some sources still suggest low-fat food, but studies haven't shown a benefit.2,6
- Treating gut bacteria imbalance (dysbiosis) with antibiotics or other treatments if your dog doesn't respond fully.1,2
- Acid-reducing medicine for some dogs that respond poorly.1,4
Mixing enzymes into food ahead of time isn't necessary.1 A few dogs get mouth bleeding or sores from the powder; this usually settles when the amount is reduced, so tell your vet.1,5
What to Expect and Life Expectancy
- Diarrhea often improves within days to 2 weeks of starting enzymes, and dogs usually regain weight quickly.4,8,1
- About 1 in 4 dogs responds poorly at first, often because of low B12, gut bacteria imbalance or another gut disease, which can often be treated.6,1
- Most dogs need enzymes for life. EPI from chronic pancreatitis can sometimes improve, but acinar atrophy rarely does.2,1
- With good management, dogs can live a normal life span.1,4 In one study, 19% of treated dogs were euthanized in the first year, and the cost of enzymes is a common reason owners give up.6,5 Ask your vet about ways to keep costs down.
Conditions That Look Like EPI
Chronic small-intestinal diarrhea with weight loss has many causes, including inflammatory bowel disease, food intolerance, Giardia and other parasites, gut bacteria imbalance, Addison's disease and intestinal lymphoma.5 Some dogs with EPI also have one of these, which is why a dog that doesn't respond to enzymes needs more testing.1,4 See IBD in dogs and Giardia in dogs.
Frequently Asked Questions
How do vets test a dog for EPI?
With a fasting blood test called cTLI. A result of 5.5 µg/L or lower confirms EPI. Vitamin B12 and folate are checked at the same time.
What does EPI poop look like?
Large amounts of soft, pale yellow or grey stool that looks greasy and often smells bad, usually passed more than three times a day.
Can a dog recover from EPI?
Rarely. Most dogs need enzymes in every meal for life. EPI caused by chronic pancreatitis can sometimes improve.
What is the life expectancy of a dog with EPI?
With enzymes, B12 if needed and a good diet, most dogs can live a normal life span. The first few months matter most, as dogs that respond well usually stay well.
What foods should a dog with EPI avoid?
High-fiber foods. Very low-fat diets aren't needed either. A highly digestible, low-fiber food with enzymes mixed in works for most dogs.
Does EPI get worse over time?
The loss of pancreatic tissue is usually permanent, but signs are controlled with treatment. Untreated dogs keep losing weight.
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Sources and further reading
This article was rewritten and fact-checked on October 30, 2026 against current veterinary references and specialist guidelines:
- Steiner JM. Exocrine Pancreatic Insufficiency in Dogs and Cats. Merck Veterinary Manual (professional version), reviewed and updated September 2025.
- VCA Animal Hospitals. Exocrine Pancreatic Insufficiency in Dogs. VCA Animal Hospitals (LifeLearn), updated Sep 20, 2023.
- Texas A&M University Gastrointestinal Laboratory. Serum Trypsin-Like Immunoreactivity (TLI). Texas A&M College of Veterinary Medicine, 2026 (reference interval revised March 2024).
- Exocrine Pancreatic Insufficiency in Dogs. Clinician's Brief, May 2011.
- Simpson KW. Exocrine pancreatic insufficiency. In: Pibot P, et al., eds. Encyclopedia of Canine Clinical Nutrition, 2008 (hosted by IVIS).
- Batchelor DJ, et al. Prognostic factors in canine exocrine pancreatic insufficiency: prolonged survival is likely if clinical remission is achieved. Journal of Veterinary Internal Medicine 21(1):54-60, 2007.
- Batchelor DJ, Noble PJM, Cripps PJ, Taylor RH, McLean L, Leibl MA, German AJ. Breed associations for canine exocrine pancreatic insufficiency. Journal of Veterinary Internal Medicine 21(2):207-214, 2007.
- Marks SL. Exocrine Pancreatic Insufficiency. Conference notes hosted by Auburn University College of Veterinary Medicine (n.d.).
- Moeller EM, Steiner JM, Clark LA, Murphy KE, Famula TR, Williams DA, Stamkovics ME, Vose AS. Inheritance of pancreatic acinar atrophy in German Shepherd Dogs. American Journal of Veterinary Research 63(10):1429-1434, 2002.
- Clark LA, Wahl JM, Steiner JM, Zhou W, Ji W, Famula TR, Williams DA, Murphy KE. Linkage analysis and gene expression profile of pancreatic acinar atrophy in the German Shepherd Dog. Mammalian Genome, December 2005.
- Universitair Veterinair Diagnostisch Laboratorium. Update EPI (exocrine pancreatic insufficiency testing). Utrecht University, September 2024.
- Toresson L, Steiner JM, Spodsberg E, Olmedal G, Suchodolski JS, Lidbury JA, Spillmann T. Effects of oral cobalamin supplementation on serum cobalamin concentrations in dogs with exocrine pancreatic insufficiency: a pilot study. Author manuscript (repository copy), circa 2019 to 2020.
About this article
Last updated : new page written using the Merck Veterinary Manual, the Texas A&M Gastrointestinal Laboratory, the Utrecht University laboratory, published survival and breed studies, Clinician's Brief, VCA and IVIS-hosted material; includes the research summary, signs, a causes and breeds table, cTLI results table, treatment, outlook, key takeaways and FAQ.
This page is for general information and is not a substitute for an exam by your veterinarian.
