EPI in Dogs: Exocrine Pancreatic Insufficiency

EPI in dogs (i.e. exocrine pancreatic insufficiency) occurs when a dog’s pancreas doesn’t make enough digestive enzymes. As a result, the dog has trouble digesting his or her food. Discover the signs, causes, diagnosis, treatment, and prognosis from integrative veterinarian Dr. Julie Buzby.

Did you know that many veterinarians have a favorite diagnostic test? I know it’s about as crazy as having a favorite burner on the stove, but it’s true. Mine happens to be the Gastrointestinal Panel which includes the serum TLI (trypsin-like immunoreactivity) test. This blood test evaluates for EPI (exocrine pancreatic insufficiency) in dogs.

The TLI is at the top of my list because it is easy to perform, it isn’t overly invasive or terribly expensive, and most importantly, it offers a clear-cut “yes” or “no” answer to the question of whether one of my patients has EPI. And better yet, if the test is positive, I get to explain to my worried clients that their dear dog has a treatable condition with an overall favorable prognosis.

So, if you’re a worried pet parent whose pup has just received an EPI diagnosis, or if you are just trying to educate yourself, you are in the right place. Settle in as I cover the ins and outs of EPI in dogs. Hopefully by the end of this article, you will feel equal parts informed and reassured.

What is EPI in dogs?

Exocrine pancreatic insufficiency (EPI) in dogs is a condition where the exocrine portion of a dog’s pancreas doesn’t make enough digestive enzymes. As a result, the food “goes right through the dog” and the dog is unable to absorb vital nutrients, vitamins, and minerals.

To better understand EPI, let’s talk a little bit more about the pancreas.

Pancreas 101

The pancreas is a small but mighty organ that lives tucked between the stomach and small intestine. Its important jobs are split into two main categories—endocrine pancreatic functions and exocrine pancreatic functions. Separate sets of pancreatic cells perform each of these functions.

Endocrine pancreatic functions

Since the endocrine function of the pancreas is regulating blood sugar, it tends to be the one people are more aware of. But, as a quick review, specialized clusters of cells within the pancreas called the Islets of Langerhans release insulin. Insulin decreases blood sugar levels by helping glucose move from the bloodstream into the cells of the body. As a result, the body can use the glucose for energy.

Plus, the pancreas secretes another hormone, glucagon, that can increase blood sugar levels by triggering the liver to release stored glucose when needed.

If the endocrine function of the pancreas fails, this leads to diabetes mellitus (diabetes in dogs).

Exocrine pancreatic functions

On the other hand, the pancreas also has exocrine functions, which are primarily related to digestion. The pancreatic cells responsible for exocrine functions release digestive enzymes into the small intestine. There are separate enzymes that help break down fats, proteins, and carbohydrates in the food. That way the dog’s body can absorb and use these nutrients.

In dogs with EPI, the exocrine pancreas no longer makes and releases digestive enzymes.

What are the symptoms of EPI in dogs?

Due to the lack of digestive enzymes, the signs of EPI in dogs generally relate to problems with digestion and nutrient absorption.

Some of the common clinical signs of exocrine pancreatic insufficiency in dogs include:

Weight loss

Dogs with EPI may lose weight despite having a good appetite since they can’t absorb the nutrients from the food they eat.

Increased fecal volume

Dogs with EPI tend to have, for lack of a more eloquent way to put it, giant poops. This happens because their body isn’t able to efficiently pull the nutrients out as their food travels through the gastrointestinal tract.

Changes in stool quality

Dogs with EPI often have softer stool. Or they may even have outright diarrhea. The stool may be lighter in color and sometimes it also has a greasy appearance due to a high concentration of undigested fat. And to add insult to injury, the stool of dogs with EPI is often extra smelly.

Increased appetite

Dogs with EPI often have an increased appetite (i.e. polyphagia). But even though they may be eating more, they will still lose weight due to the malabsorption of nutrients. Therefore, EPI is definitely on the list of potential reasons a dog is losing weight but eating an increased amount of food.

Poor haircoat

Most dogs with EPI will have a dull, dry, or brittle coat. It turns out that being able to absorb vitamins and nutrients is just as vital to growing long, lustrous locks in dogs as it is in people.

Vomiting

Some dogs with EPI may experience intermittent vomiting. However, it is not as common as other digestive symptoms, and vomiting will not be present in all dogs with EPI.

Dietary indiscretion

Some dogs with EPI experience an urge to eat non-food items like poop (i.e. coprophagia), rocks, or dirt due to the nutrient deficiencies caused by their condition. This urge to eat non-food items is also called pica.

Increased gassiness and digestive noises

Undigested nutrients left in the GI tract are good food for the bacteria that normally live there. This can lead to fermentation and extra gas production. As a related aside, the scientific term for extra noisy GI rumblings, borborygmus (bor-bo-RIG-mus), is one of my favorite medical words!

What are the causes of EPI in dogs?

The pancreas is another organ, like the liver and kidneys, that is built to have a lot of reserve function. So, by the time you notice any symptoms of something amiss with your beloved canine companion, he or she will have lost more than 90% of the exocrine pancreatic function. This loss of exocrine function can occur for a variety of reasons.

Pancreatic acinar atrophy (PAA)

The most common cause of EPI in dogs is pancreatic acinar atrophy (PAA). In dogs with PAA, the acinar cells of the pancreas, which make digestive enzymes, are progressively destroyed. The exact underlying cause of PAA is still unknown, but it seems to be an autoimmune condition. This means that the body’s own immune system is responsible for the destruction of the acinar cells.

PAA is at least in part heritable. This means that PAA, and therefore EPI, are more common in certain breeds. German Shepherd dogs are the poster child for EPI. In fact, German Shepherds account for roughly two-thirds of the dogs diagnosed with EPI due to PAA , according to one study.

Breeds predisposed to EPI due to PAA include:

• German Shepherds
• Rough-Coated Collies
• Eurasians
• Chow Chows

Thankfully, PAA does not normally affect the endocrine function of the pancreas. This means these dogs are not at an increased risk of developing diabetes.

The age of onset for dogs with EPI caused by pancreatic acinar atrophy is earlier on in life. Most dogs receive this diagnosis somewhere between adolescence and middle age, in the range of two to five years old.

Chronic pancreatitis

The second most common cause of exocrine pancreatic insufficiency in dogs is chronic pancreatitis. The inflammation of the pancreas, if severe and ongoing, can damage the pancreatic tissue of dogs and cats. Over time, this can lead to the destruction of the cells responsible for producing digestive enzymes, causing exocrine pancreatic insufficiency.

Most dogs who get pancreatitis will not end up with EPI. But if your pup has a history of severe or recurrent pancreatitis and begins to experience any of the signs listed above, reach out to your veterinarian to discuss whether or not you should consider testing for EPI.

Dogs with EPI secondary to chronic pancreatitis are also at risk of developing diabetes, either concurrently or after the EPI diagnosis. This is the case because the inflammation that damages the pancreas does not discriminate. It can damage cells responsible for both the endocrine and exocrine pancreatic function.

Dogs with EPI secondary to chronic pancreatitis are likely to be middle age to older. And it also makes sense that dog breeds more likely to have chronic pancreatitis are predisposed to developing EPI as well. These breeds include:

• Cavalier King Charles Spaniels
• Cocker Spaniels
• West Highland White Terriers
• Cairn Terriers

Cancer

Pancreatic cancer can lead to EPI if enough of the pancreatic cells that produce digestive enzymes are destroyed. Masses of the pancreas or small intestine that block the pancreatic duct can also lead to the same signs as EPI. In these cases, the pancreas is still able to make digestive enzymes. But the tumor is blocking the release of these enzymes into the small intestine.

In general though, cancer is an uncommon cause of EPI in dogs.

Congenital disorders

Congenital pancreatic hypoplasia is a rare, and somewhat controversial, potential cause of EPI in very young puppies. It is hypothesized that dogs with congenital pancreatic hypoplasia are born without enough exocrine pancreatic cells. However, this scenario has not be been backed up with the pancreatic biopsy data necessary to prove the existence of such a condition.

How will the vet diagnose EPI?

Regardless of the cause of the EPI, the clinical signs are often specific enough that you and your veterinarian may be highly suspicious of this condition right off the bat. After your veterinarian takes a thorough history, the next step will be a comprehensive physical exam. Then he or she will discuss further diagnostics.

Bloodwork and a urinalysis

The combination of a complete blood count, chemistry profile, and urinalysis is always a good starting place for any sick pet. These tests are great at ruling out other conditions that might cause similar signs of weight loss despite a good appetite, like diabetes mellitus.

Most of the time dogs with EPI won’t have any major abnormalities on the screening blood tests for dogs and urinalysis.

Trypsin-like immunoreactivity (TLI)

As I hinted at in the introduction, the good news is that the next step involved in testing for and diagnosing EPI is relatively straightforward. The canine serum trypsin-like immunoreactivity (TLI) test is the definitive test for diagnosing EPI. This blood test measures blood levels of trypsinogen, a pancreatic enzyme. Low TLI levels indicate a deficiency in pancreatic enzyme production. And they are consistent with a diagnosis of EPI.

This TLI test is a simple blood test, though your veterinarian will need to send it to an outside lab. Thus, results may take a week or more to return. One important detail to consider is that your dog will need to be fasted prior to the TLI test. So make sure you check with your veterinarian about his or her specific fasting instructions before your visit. The general rule of thumb is a 12-hour fast prior to this blood test.

The majority of the time this test will either return above a certain threshold that rules out EPI or below a certain threshold that diagnoses EPI. Occasionally, the value falls in a borderline zone. In this case, the vet will recommend repeating the test in roughly a month. Very rarely, for example in cases with a pancreatic duct obstruction or in patients with severe kidney failure in dogs, the TLI value can be normal in a dog who does in fact have EPI.

Measuring B12 and folate levels

Most of the time, the TLI blood test is a part of a larger blood panel that also tests folate and vitamin B12 levels. Folate and vitamin B12 are vitamins absorbed by the GI tract. So their levels can give important clues regarding your dog’s gut health.

Normally, the pancreas secretes a protein called intrinsic factor. It allows for the absorption of vitamin B12 across the small intestine. Dogs with EPI don’t make enough of this protein, which means B12 is unable to cross into circulation. Therefore, checking the vitamin B12 levels is important. Low B12 levels are common in the majority of patients with EPI and are also a poor prognostic indicator.

Folate, another type of B vitamin, can be either low, normal, or high in dogs with EPI. If folate levels are low, this helps the vet know that the dog could benefit from a folate supplement. And if folate levels are high, this might indicate bacterial overgrowth in the small intestines that the vet can treat with specific antibiotics.

Imaging

In some cases, your veterinarian may suggest imaging studies as part of the diagnostic process. Most commonly this would be an abdominal ultrasound, which allows for visualization of the pancreas and surrounding structures. This can help identify any structural abnormalities or inflammation of the pancreas and GI tract. And it can also assess for other health issues that could be contributing to your beloved canine companion not feeling his or her best.

Work with your vet to create a diagnostic plan

Remember, the diagnostic process may vary based on your dog’s specific circumstances. It’s crucial to work closely with your veterinarian to determine the most appropriate tests and develop a tailored plan for your pup.

What is the treatment for EPI in dogs?

Once the vet diagnoses your dog with EPI, he or she will work with you to formulate a treatment plan. It may involve the following components:

Pancreatic enzyme supplementation

Treatment for dogs with EPI is relatively straightforward in most cases. The mainstay of treatment is supplementing affected dogs with the pancreatic enzymes they are missing. These enzymes can be supplemented as either prescription tablets, capsules, or powders. Previously, powders were thought to be more effective. But recent studies seem to indicate that tablets and capsules can work well for many dogs.

Pancreatic enzymes must be supplemented with every meal for the rest of your dog’s life. These enzymes essentially do the job that your dog’s pancreas can no longer do. They allow the nutrients from each meal to be broken down into the forms that are able to be absorbed across the GI tract.

Pre-mixing the enzymes with the food and letting them sit before feeding does not make them work any better. But it can sometimes help prevent mouth irritation, which is a common side effect of pancreatic enzyme supplementation.

Your veterinarian will likely give you a starting dose for the pancreatic enzymes. And then depending on response to treatment, he or she can either adjust it upwards or downwards.

Occasionally, some dogs might not do well with the powders, tablets, or capsules. In those cases, you can use chopped, raw pork or cow pancreas instead.

However, it is important to know that feeding raw food does come with an increased risk of food-borne illness for both furry and non-furry members of the household. If you do decide to go this route it is important to consult with your veterinarian. He or she can advise you about the proper amount of pancreas to feed. And your vet can tell you what precautions to take to try to keep everyone in the household safe.

Vitamin B12 supplementation

Since most dogs with EPI have low vitamin B12 levels, supplementation with B12 is generally part of ongoing management for EPI in almost all cases. Even if vitamin B12 levels are normal at first, and the dog has started treatment with pancreatic enzymes, low B12 levels can develop later.

The good news is that vitamin B12 is a very safe vitamin to supplement since it is water soluble. This means that any extra that your dog doesn’t need will just be peed out. Since low vitamin B12 levels can negatively impact the survival of dogs with EPI, it is generally better to be safe and supplement your dog with this vitamin long-term.

Your dog can have vitamin B12 injections weekly at first and then monthly. Or your dog can take a daily B12 supplement as an oral tablet.

Antibiotics

As noted above, some dogs with EPI will have an overgrowth of bacteria within their small intestinal tract due to the residual nutrients they are unable to absorb. Even if bacterial overgrowth is present, many dogs are not clinically affected and so do not need treatment.

However, if your dog is not responding well to traditional treatment with pancreatic enzymes and B12, your veterinarian might consider a course of antibiotics. This can be helpful in case small intestinal bacterial overgrowth or dysbiosis (i.e. imbalance in gut bacteria) are contributing to the lack of resolution of the clinical signs.

Diet change

There is not one specific type of diet that is recommended for dogs with EPI. And it might take a period of trial and error before you and your veterinarian find the ideal diet that works for your dog. In most cases, dogs with EPI respond well to prescription diets that are specifically formulated to be highly-digestible and that have moderate fat levels, higher energy density, and lower fiber levels.

Partnership with your vet

Regardless of the specific treatment regimen, it is important to keep in close touch with your veterinarian. And you should also schedule regular check-ups for your beloved canine companion. Your veterinarian can monitor your dog’s progress and can work with you to adjust the treatment plan as needed.

The diagnosis and treatment are theoretically straightforward. But the reality is that having a dog with EPI can be a bit of a journey. A strong relationship with your veterinarian and a healthy dose of patience can only improve the odds that you will ultimately get to watch your dog thrive on his or her individualized treatment plan!

What is the prognosis and life expectancy for dogs with EPI?

EPI is a chronic condition and requires lifelong management. However, the prognosis for dogs with exocrine pancreatic insufficiency is generally positive with proper management and treatment.

Veterinary studies indicate that the majority of patients with EPI respond well to treatment and can have a normal life expectancy. But some studies have shown that around one in five patients may have a poor response and a shorter life expectancy.

Cost can also be a consideration. The financial investment of both pancreatic enzyme supplementation and the long-term veterinary care required for this condition can be a challenge for some families.

Work with your vet to optimize your dog’s EPI treatment

The goal for dogs with EPI is an improvement in their clinical signs. With the correct treatment regimen, most dogs should gain weight, have improved stool quality and coat condition, and benefit from increased energy levels.

But if you find that your dog’s signs are not improving as you had hoped after starting treatment, don’t be disheartened. There are many tweaks your vet can make to your dog’s treatment protocol to optimize the response. Just remember to reach out to your veterinarian promptly so he or she can help advise you.

You are your beloved canine companion’s staunchest and most valuable advocate. Don’t underestimate your role in working alongside your veterinarian to get your precious pup back to a place where he or she is feeling great and able to live out a long and happy life with you.

Has your dog been diagnosed with EPI?

Please share his or her story in the comments.