Hey there, pet parents. Have you ever had a dog that seems to eat and eat and eat, but is still rail thin and has voluminous, greasy diarrhea? If so, you might be looking at a condition called Exocrine Pancreatic Insufficiency (EPI). This is a serious condition, but the great news is that it's very treatable! Let's dive in.
What is Exocrine Pancreatic Insufficiency (EPI)?
Remember how we talked about the pancreas having two jobs? One is to produce insulin (the endocrine function), and the other is to produce digestive enzymes (the exocrine function).
In EPI, the exocrine part of the pancreas fails. The cells that are supposed to produce the digestive enzymes have atrophied or been destroyed, so the pancreas no longer secretes the enzymes needed to break down food.
Without these enzymes, your dog can't digest or absorb the nutrients from their food, no matter how much they eat. The undigested food just passes right through them. This is why it's called a "maldigestion" or "malabsorption" disorder.
What Causes EPI?
By far, the most common cause of EPI in dogs is a genetic condition called pancreatic acinar atrophy. This is an autoimmune disease where the dog's own immune system attacks and destroys the enzyme-producing cells of the pancreas. This is most commonly seen in German Shepherds, who are the poster children for EPI. It can also be seen in Rough-Coated Collies.
The other major cause is chronic pancreatitis. Over time, repeated bouts of inflammation can destroy the pancreatic tissue, leading to both EPI and, sometimes, diabetes (if the insulin-producing cells are also destroyed).
Spotting the Signs of EPI
The classic signs of EPI are very striking:
- •Ravenous Appetite (Polyphagia): Your dog is hungry ALL the time. They might even start eating things they shouldn't (pica).
- •Severe Weight Loss: Despite the huge appetite, they are losing weight and look emaciated. Their muscles are wasting away.
- •Voluminous, Greasy, Pale Stools (Steatorrhea): This is the hallmark sign. They have large amounts of soft, "cow-patty" diarrhea that is often yellowish or grayish in color and looks very greasy. The smell is often terrible.
- •Poor Coat Quality: Their coat may be dry and dull.
Basically, you have a dog that is starving in the face of plenty. All the food is passing right through them without being absorbed.
How Vets Diagnose EPI
The diagnosis of EPI is actually very straightforward. If a vet sees a dog with the classic signs (especially a German Shepherd), they will be highly suspicious.
The diagnosis is confirmed with a simple blood test called a Trypsin-Like Immunoreactivity (TLI) test.
- •Trypsin is one of the digestive enzymes produced by the pancreas. A small amount of it normally "leaks" into the bloodstream.
- •The TLI test measures the amount of trypsin in the blood.
- •In a dog with EPI, the pancreas is not producing trypsin, so the level in the blood will be very, very low.
A low TLI in a dog with the right clinical signs is a slam-dunk diagnosis for EPI. Your vet will also check for vitamin deficiencies, especially Vitamin B12 (cobalamin), which is almost always low in dogs with EPI.
Treatment: It's All About Enzyme Replacement
The treatment for EPI is also very straightforward and is aimed at replacing the digestive enzymes that the pancreas is no longer making.
- •Pancreatic Enzyme Supplementation: This is the cornerstone of treatment. You will need to add a powdered pancreatic enzyme supplement to your dog's food for the rest of their life. This powder contains the lipase, amylase, and protease that your dog is missing. You simply mix the prescribed amount of powder into your dog's food right before you feed them. There is no need to let it "incubate."
- •Diet: Most dogs with EPI do well on a high-quality, highly digestible commercial diet. Sometimes, a low-fiber diet is helpful.
- •Vitamin B12 (Cobalamin) Supplementation: Because the damaged intestine can't absorb B12, almost all dogs with EPI will need to have B12 supplementation. This is usually given as an injection under the skin, initially once a week, and then tapered to once a month for life.
- •Antibiotics: Many dogs with EPI have an overgrowth of bad bacteria in their gut (a condition called SIBO - Small Intestinal Bacterial Overgrowth). A course of antibiotics, like tylosin or metronidazole, is often needed initially to get this under control.
Prognosis
The great news is that the prognosis for dogs with EPI is excellent! With consistent enzyme and vitamin supplementation, these dogs can live a completely normal, happy life. The diarrhea will resolve, they will gain weight, and their appetite will return to normal.
The key is lifelong management. You can never stop the enzyme supplementation. It can be expensive, but it will give you your happy, healthy dog back.
Sources & Further Reading:
- •VCA Animal Hospitals - Exocrine Pancreatic Insufficiency in Dogs
- 1Merck Veterinary Manual - Exocrine Pancreatic Insufficiency in Small Animals