Exocrine Pancreatic Insufficiency (EPI)

Summary

The pancreas is an organ with a variety of functions. Among them is the ability to secrete enzymes and other factors that aid in digestion at the level of the small intestine. We refer to this as its "exocrine" function. When most of the pancreas that functions to secrete these important digestive molecules is adversely affected, the result is a disease process we call "exocrine pancreatic insufficiency" or "EPI."

The causes of this relatively common process in both dogs and cats are various. In dogs, "pancreatic acinar atrophy" or "PAA" is the primary cause and it affects the acinar cells responsible for enzyme secretion. It occurs for reasons we don't understand and is known to have a hereditary basis.

In cats, chronic pancreatitis (swelling of the pancreas over a long period of time) is most typically the cause of the loss of function in these important cells. For both dogs and cats, chronic or recurrent bouts of pancreatitis along with pancreatic cancers can also be responsible for EPI.

When most of the pancreas's exocrine function has been affected, digestion of the foodstuff in the small intestine fails to take place normally. The result is bacterial overgrowth, poor nutrient absorption and major changes to the lining of the small intestine over time.

Symptoms and Identification

Pets with EPI typically suffer severe, voluminous diarrhea as a result of their intestinal bacterial overgrowth and malabsorption of nutrients. The inability to take in nutrients also results in unthriftiness, weight loss and poor skin coats, among other signs of poor body condition. Though most pets will eat ravenously to compensate for their malassimilation of nutrients, cats in particular may suffer bouts of anorexia.

Though these signs are typical of EPI, many other diseases may cause similar symptoms (intestinal parasites, SIBO, lymphangiectasia, etc), thereby complicating its diagnosis. Veterinarians have to elect very specific laboratory tests in order to confirm the presence of EPI (which may also be complicated by the presence of pancreatitis).

The fTLI and cTLI are blood tests specific to feline and canine pets, respectively. A new test, the PLI, has recently been found to be even more sensitive and specific. Another test which evaluates fecal matter measures elastase activity. It's now being used as a screening test for EPI, though normal pets may sometimes test positive, as well.

Affected Breeds

In dogs, German Shepherds, Collies and English Setters are known to be predisposed to PAA, which leads to this deficiency of the exocrine pancreas. In cats, breed predilections have not been well established.

Treatment

The cornerstone of EPI treatment is lifetime administration of pancreatic enzyme supplements. Powdered pancreatic extracts are the most common mode of delivery. Dietary management is also important. Though the need of a low-fat diet is sometimes debated, most pets seem to improve with these diets. Vitamin supplementation is also deemed essential: cobalamin, vitamin K and oral vitamin E supplements are always recommended for these patients.

Because some of these pets also suffer small intestinal bacterial overgrowth or inflammatory processes of the intestine, antibiotic and anti-inflammatory drugs are sometimes required on a periodic or ongoing basis for successful EPI treatment.

Veterinary Cost

Though this condition can be time-consuming to manage as it requires owners to administer a lifetime of medications, special diets and supplements, it's a relatively inexpensive disease to handle.

Blood tests to diagnose the problem and other tests to rule out other major disease processes may well rack up significant bills ($300 to $1000 or more), but even the long-term need for dietary management doesn't typically add up to more that another $20 to $100 every month, depending on the size of the affected animal.

Prevention

The only known mode of EPI prevention is via elimination of affected patients from any breeding programs.

References

Adamama-Moraitou KK, Rallis TS, Papasteriadis A, et al. Iron, zinc and copper concentration in serum, various organs and hair of dogs with experimentally induced exocrine pancreatic insufficiency. Digestive Diseases and Sciences, 2001, 46(7), 1444-1457.

Adamama-Moraitou KK, Rallis TS, Papazoglou, et al. Liver biochemical and histopathological findings in dogs with experimentally induced exocrine pancreatic insufficiency. The Canadian Journal of Veterinary Research, 2004, 68, 56-61.

Adamama-Moraitou KK, Rallis TS, Prassinos NN, et al. Serum vitamin A concentration in dogs with experimentally induced exocrine pancreatic insufficiency. International Journal for Vitamin and Nutrition Research, 2002, 72, 177-182.

Rallis TS, Adamama-Moraitou KK, Soubasis N. Canine exocrine pancreatic insufficiency: Clinical and laboratory findings in 15 spontaneous cases. Canine Practice, 1999, 24, 12-15.