Exocrine Pancreatic Insufficiency (EPI) in Dogs and Cats
Exocrine Pancreatic Insufficiency (EPI) is a syndrome that is characterized by a lack of effective pancreatic exocrine secretion in the small intestine.EPI is not a rare clinical condition in both dogs and cats. The most common cause of EPI in dogs is pancreatic acinar atrophy (PAA). The etiopathogenesis of PAA has not yet been determined. Although PAA has been reported in many breeds, a familiar predisposition exists in German Shepherd dogs, collies and English setters. Chronic pancreatitis, repeated episodes of acute or subacute pancreatitis and pancreatic neoplasia are also reported as a cause of canine EPI. In cats chronic pancreatitis is the most common cause of EPI. Eurytrema procyonis flukes attached in the pancreatic ducts have been reported as a cause of EPI in some cats.
The pancreas is an accessory digestive gland that functions as both an exocrine and an endocrine gland. Endocrine functions involve the release of hormones directly into the blood stream. The other function of the pancreas is the secretion of digestive enzymes by way of the pancreatic ducts directly into the intestinal tract where they aid in the digestion. The pancreas secretes enzymes that break down virtually all digestible molecules to a form that can be absorbed.
There are three major groups of enzymes critical to efficient digestion:
- Proteases (breaks down proteins)
- Lipase (breaks down fats)
- Amylase (breaks down starches)
Additionally, bicarbonate is secreted from cells in the lining of the pancreatic ducts. Not surprisingly the secretion of these enzymes is regulated by other hormones—a truly amazing interrelationship. The mixture of these chemicals with the addition of water is necessary for digestion and absorption of nutrients. Without these enzymes, digestion of food is not complete and absorption of nutrients is hindered. The result is what appears to be starvation in the face of adequate food intake.EPI is characterized by loss of the majority of the functional reserve capacity of the exocrine pancreas. Therefore, a decrease of intraduodenal concentration of pancreatic enzymes, bicarbonate, antibacterial and enteric mucosal “trophic” factors, as well as pancreatic and GI regulatory peptides are observed. Finally, malassimilation of nutrients (fats, carbohydrates, proteins, vitamins, trace elements), small intestinal bacterial overgrowth, morphologic and functional changes of small intestine are produced as a result of EPI.
Dogs and cats with EPI usually have a history and clinical signs of small bowel diarrhoea with voluminous, semiformed, yellowish or gray feces, polyphagia, pica especially in young dogs with inherited EPI, extreme weight loss, intestinal borborygmus, and dermatological problems such as poor coat and seborrhoea sicca. Anorexia has also been observed in some cats.Although the symptoms of EPI are typical, they are not pathognomonic. In dogs, the differential diagnosis includes the small intestinal disorders that cause malabsorption or maldigestion (intestinal parasites, inflammatory bowel disease, small intestinal villus atrophy, lymphangiectasia, diffuse small intestinal malignancies, short bowel syndrome, changes of the intestinal brush border enzyme activities). Differential diagnosis in cats includes intestinal parasites, inflammatory bowel disease, hyperthyroidism, chronic renal failure and triaditis (chronic pancreatitis-cholangiohepatitis-inflammatory bowel disease) and intestinal lymphoma.
Routine haematology results are usually within normal limits. Liver enzyme activity such as serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase are mildly increased and may reflect hepatocyte damage secondary to increased uptake of hepatotoxic substances through an abnormally permeable small intestinal mucosa or hepatic lipidosis. Concurrent hyperglycemia or abnormal glucose tolerance test are not common in dogs with EPI. Some dogs have subnormal cobalamin and high folate concentration. Cats with EPI have decreased serum cobalamin and folate concentration. Serum vitamin E and A concentrations are decreased in dogs, while serum vitamin K is decreased in some cats with EPI. Absorption of trace elements in EPI may be promoted or inhibited secondary to either loss of specific factors affecting absorption or to a change in intraluminal pH. In experimentally induced EPI in dogs, as well as in some clinical cases, serum total iron concentration and % transferring saturation have been increased, while serum copper and zinc concentration have been decreased.
The histopathological lesions of dogs with EPI include pancreatic atrophy and fibrosis, foci of fatty infiltration in the liver, destruction of villi epithelium and infiltration of small intestinal lamina propria with lymphocytes and plasmacytes.The confirmation of clinical diagnosis of EPI is based on the measurement of serum trypsin-like immunoreactivity (cTLI) by radioimmunoassay. The cTLI is a species and pancreas specific test and determines trypsin and trypsinogen that have entered the blood from pancreas. The values of TLI test are characteristic and help in differentiating EPI of small intestinal diseases. Low-fasting serum cTLI concentrations (< 2.5 μg/L) are typical of EPI. Reference range of TLI in normal dogs is 5.0 to 35 μg/L. cTLI values between 2.5-5 μg/L are indicative of early phase of EPI, before severe destruction of exocrine pancreas.
A new fecal test for diagnosis of EPI is based on the determination of fecal elastase activity using the ELISA method. It is also a species and pancreas–specific test. A single fecal sample is sufficient and values less than 10 μg/g are suggestive of EPI. A disadvantage of this test is that low results can occasionally be found in normal dogs.
The fasting serum feline TLI test (fTLI) was developed and validated for the diagnosis of EPI in cats. Values of less than 8 μg/L are suggestive of EPI. fTLI values between 8-17 μg/L are indicative of early phase of EPI. For the diagnosis of exocrine pancreatic disorders, a radioimmunoassay has been recently developed and validated that measures canine and feline pancreatic lipase immunoreactivity (PLI). The PLI test is more sensitive and specific than TLI test.The management of EPI is based on the dietary modification and pancreatic enzyme supplementation. A highly digestible, lowfat, low-fiber diet has been shown to ameliorate clinical signs of EPI. On the contrary, some small animal gastroenterologists insist that feeding a low-fat diet does not significantly improve clinical symptoms. Dietary supplementation of medium-chain triglyceride oil (2 ml/meal every other day) may further improve the patient situation.Exogenous pancreatic enzyme supplementation is the cornerstone of treatment of canine and feline EPI. Powdered pancreatic extracts (2 teaspoons/20 kg BW/meal for dogs, 0-1 teaspoon/cat/meal for cats) are usually adequate. The powdered form of pancreatic extracts is more suitable compared to the enteric-coated tablets, capsules or raw-chopped pancreas. Dogs and cats with EPI require parenteral cobalamin, vitamin K and oral vitamin E supplementation.
Inadequate enzyme supplementation may be a cause of treatment EPI failure. In these cases reevaluation of dose is indicated. Lipase is acid-sensitive enzyme. In some dogs with EPI the enzyme supplementation must followed by an antacid administration (ranitidine, cimetidine).
Other causes of treatment failure in dogs with EPI are small intestinal bacterial overgrowth and/or inflammatory small intestinal disease. In these cases metronidazole and/or prednisone administration is respectively indicated.
EPI is a condition in which your pet’s pancreas is unable to make enough digestive enzymes to break down the food they eat. This means that your pet cannot digest and absorb nutrients from their food, causing them to become malnourished.
What are the signs that your pet may have EPI?
The most common signs of EPI in dogs include:
- Loose “pulpy” feces, which may have a clay-color
- Weight loss despite a good appetite
- Occasional vomiting
- Poor hair coat (hair is dry and brittle)
- Eating feces (poop) or other objects.
Clinical signs can be more subtle in cats than in dogs and may include:
- Weight loss
- Poor hair coat (hair is dry and brittle)
- Either an increased or decreased appetite
- Vomiting and watery diarrhea are less common in cats than in dogs.
Your pet may also show other clinical signs depending on the underlying cause of EPI.
What are the causes of EPI?
The most common cause of EPI is a lack of the cells that make digestive enzymes. Cells can be lacking due to wasting away (atrophy), damage from inflammation, a blockage of the pancreatic duct, or other causes. In most cases, there are no digestive enzymes at all; however, in rare cases, just one enzyme may be missing in your pet.
Any dog or cat can develop EPI. Some dog breeds may be more likely to develop EPI than others, including young German Shepherds, Rough-Coated Collies, and Eurasiers. Cavalier King Charles Spaniels may be predisposed to EPI following chronic inflammation of the pancreas, also known as pancreatitis. Domestic shorthair cats may also be more likely to have EPI.
What tests are required?
After getting a complete history and performing screening tests to rule out other problems, a simple blood test can be used to diagnose EPI. This test is called trypsin-like immunoreactivity (TLI) and its concentration is low in dogs or cats with EPI. Your veterinarian may also evaluate your pet’s feces (poop) for the presence of fat and to rule out parasites. The TLI test is recommended to be performed along with measurement of cobalamin (B12) which is a vitamin that is commonly low in pets with this disease.
What is the treatment for EPI?
Daily pancreatic enzyme supplementation is the standard treatment for EPI. Your vet will prescribe these supplements, which you will then add to your pet’s food to help ensure they get the enzymes they need. Supplements usually come as a powder, capsule or tablet. Side effects of enzyme supplementation are rare but may include bleeding of the mouth. When this happens, some veterinarians will prescribe raw, chopped beef or pork pancreas for your pet to eat.
Your vet may also recommend that you change your pet’s diet. Typically, novel protein or hydrolyzed diets are prescribed. Novel protein diets use protein sources your pet hasn’t seen before such as kangaroo, venison, alligator, etc. Hydrolyzed diets are made so that the proteins themselves are so small that they are unlikely to cause an adverse food reaction. Cobalamin (B-12) supplementation is also commonly prescribed in both dogs and cats with EPI.
If your pet does not respond to standard treatment, your veterinarian may try a different brand or formulation of pancreatic enzymes or may alter the dose until they find the best treatment for your pet. Occasionally other medications (gastroprotectants, probiotics, or antibiotics) may also be used to improve your pet’s response. Your veterinarian may also look for more evidence of other diseases, such as intestinal problems, which could occur at the same time as EPI and may cause similar symptoms.
Treatment Options for Pets with Exocrine Pancreatic Insufficiency
Treatment is chronic/lifelong. Your vet will prescribe your pet a pancreatic digestive enzyme powder (or tablet/capsule) to mix into your pet’s meals daily. Your vet should prescribe the amount of enzyme and monitor progress until the lowest amount needed to maintain a healthy pet has been ascertained. This may take weeks to months, depending on each animal and their condition when first presented to the vet. You may also discuss feeding raw pancreas as an alternative to enzyme powders with your vet. Sadly, many animals may have this condition and it goes undiagnosed or misdiagnosed for some time before treating it properly.
Supplementing your pet’s pancreatic enzymes will stop clinical signs but does not normalize the absorption of fats. Although there are low-fat diets that may help decrease this problem, in turn, the pet may develop fat-soluble vitamin deficiencies. Diets with fermentable fiber such as beet pulp are preferred over diets with insoluble/nonfermentable fiber, which can interfere with pancreatic enzyme activity. Discuss what diet to feed your pet with your veterinarian.Deficiencies in cobalamin (vitamin B12) occur due to decreased absorption without the help of ‘intrinsic factor’, an exocrine pancreatic enzyme whose production is decreased due to damaged cells. Vitamin B12 can be supplemented with injections and/or oral supplements. Injections are often preferred since the intestinal tract may not absorb the B12 well enough.If animals don’t respond to these treatments, they may have other gastrointestinal illnesses that need to be addressed and treated, such as an imbalance of bacteria in the intestinal tract, inflammatory bowel disease, and more.Pets that are diagnosed early and treated appropriately and consistently can live a full, long, and happy life just like a pet without EPI.
Preventing Exocrine Pancreatic Insufficiency
Although you cannot prevent the genetics leading to the development of EPI in young dogs of certain breeds, you can certainly try your best to prevent pancreatitis in ALL pets, and therefore chronic pancreatitis, and potentially EPI. Avoid feeding your pet any buttery or oily table scraps, any high-fat content foods, and always feed a balanced pet food appropriate for your pet’s species and life stage.
What is the outcome after treatment?
Most pets with EPI have a good quality of life and a normal life expectancy with ongoing treatment. Your pet should get regular check-ups to ensure the treatment is working and that they are getting the nutrition they need throughout their life.
Compiled & Shared by- Team, LITD (Livestock Institute of Training & Development)
Image-Courtesy-Google
Reference-On Request.
