By Dial A Vet Veterinary Team
A dog that eats everything in sight yet keeps getting thinner, and passes large, pale, greasy stools, is showing the textbook picture of exocrine pancreatic insufficiency (EPI). The pancreas has stopped making enough digestive enzymes, so food passes through largely undigested and the body starves despite a full bowl. EPI is most common in young German Shepherds, but it also occurs in other breeds and in cats. The good news is that once it is diagnosed, most pets regain weight on lifelong enzyme replacement and careful management.
Key takeaways
- EPI means the pancreas produces too few digestive enzymes to break down fat, protein, and starch.
- Classic signs are weight loss with a big appetite, bulky pale or greasy stools, and flatulence.
- In dogs it is often inherited (German Shepherds and Rough Collies especially). In cats it usually follows chronic pancreatitis.
- A specific blood test (serum TLI) confirms the diagnosis.
- Treatment centres on enzymes mixed into every meal, vitamin B12 when levels are low, and diet adjustments guided by your vet.
What causes EPI
The pancreas has two jobs. One part makes insulin and other hormones, and the other part (the exocrine pancreas) makes enzymes that are released into the gut to digest food. EPI develops when most of that enzyme-producing tissue is lost.
- Pancreatic acinar atrophy. The most common cause in dogs. The immune system gradually destroys the enzyme-producing cells, typically in young adult dogs. German Shepherds, Rough Collies, and Chow Chows are overrepresented.
- Chronic pancreatitis. Repeated or long-term inflammation scars the pancreas. This is the main cause in cats and in older dogs. Read more about pancreatitis in dogs and pancreatitis in cats.
- Less common causes include pancreatic tumours or surgery.
Because chronic pancreatitis can damage both parts of the pancreas, some pets with EPI also develop diabetes.
Signs to watch for
- Weight loss or poor growth despite eating well, sometimes ravenously
- Large volumes of soft, pale, or greasy stools, often with a strong smell
- More frequent toileting
- Excess wind and gurgling gut noises
- Eating faeces or non-food items
- A dull, poor coat
- In cats, greasy, matted fur around the tail and bottom
Cats with EPI do not always show a big appetite and may simply look thin and unkempt with loose stools, which is one reason EPI in cats is easy to miss.
When to see a vet
Go to an emergency vet now if your pet:
- Is vomiting repeatedly, cannot keep water down, or seems dehydrated and flat
- Has collapsed, is very weak, or has a painful, tense belly
- Is drinking and urinating far more than usual and has become lethargic (a possible diabetic crisis)
Book a same-day appointment if: your pet has stopped eating, has diarrhoea with blood, or a known EPI patient suddenly worsens.
Book a routine appointment soon if: your pet is losing weight while eating well, or loose, pale stools have continued for more than a week or two. Weigh them if you can and take a photo of a typical stool.
How vets diagnose EPI
The key test is serum trypsin-like immunoreactivity (TLI), a blood test usually taken after a short fast. A very low result confirms EPI. Your vet will often also check vitamin B12 (cobalamin) and folate levels, as B12 deficiency is very common with EPI, particularly in cats, and can hold back recovery on its own. General blood tests and a faecal check help rule out other causes of weight loss and diarrhoea, such as parasites or inflammatory bowel disease.
How vets typically manage EPI
- Enzyme replacement. Pancreatic enzymes are added to every meal for life. Your vet will advise on the product and how to prepare it, and will fine-tune the amount based on weight gain and stool quality. Do not change it without checking in.
- Vitamin B12. Given when levels are low, often by injection, with rechecks to see when it is needed.
- Diet. A consistent, highly digestible food is usually recommended. Your vet will guide whether fat or fibre levels need adjusting.
- Gut bacteria. Some pets develop an imbalance of intestinal bacteria and need additional treatment while they stabilise.
Many pets show firmer stools within days and gain weight over the following weeks. Ongoing weigh-ins help your vet track progress. A small number respond poorly at first and need more investigation.
Living with an EPI pet
- Keep a simple diary of weight, appetite, and stool quality, especially in the first few months.
- Never skip enzymes, including for treats that contain meaningful calories. Ask your vet which treats are suitable.
- Keep enzyme products stored as directed so they stay effective.
- Watch for signs of diabetes, such as increased thirst and urination.
- Tell breeders if your dog was diagnosed young, since the inherited form runs in families.
FAQ
Can EPI be cured?
EPI is usually permanent, so treatment is lifelong. With good management most pets live a normal lifespan.
Is EPI common in cats?
It is less common than in dogs, but it is probably under-recognised. It usually follows chronic pancreatitis.
How quickly do pets improve on enzymes?
Stools often improve within days, and steady weight gain over several weeks is typical. If not, your vet will look for complicating factors.
Is EPI the same as pancreatitis?
No. Pancreatitis is inflammation of the pancreas. EPI is a loss of enzyme production, which can be a long-term result of repeated pancreatitis.
Talk with a vet
If your pet is losing weight despite a good appetite, or you are managing EPI and want help interpreting stool or weight changes, our vets can talk it through by video. Book a consult at dialavet.com. Diagnosis needs a blood test, so we will point you to your clinic when testing is due, and a pet that is vomiting, collapsing, or very flat should go straight to a hospital.
References
- Merck Veterinary Manual. Exocrine Pancreatic Insufficiency in Small Animals.
- Texas A&M Gastrointestinal Laboratory. Information on TLI and cobalamin testing.
- Cornell Feline Health Center. Pancreatic disease in cats.
- VCA Animal Hospitals. Exocrine Pancreatic Insufficiency in Dogs.
Disclaimer: Educational only. This page does not replace an examination or advice from your own veterinarian. Never change enzyme or other treatment without speaking with your vet.
