Inability of the body to properly digest food due to lack of pancreatic enzymes (digestive enzymes) is termed as Exocrine Pancreatic Insufficiency (EPI).
The pancreas is a small, light pink glandular organ located under to the stomach and next to the upper portion of the small intestine (duodenum). It has two separate functions within the body, often referred to as the exocrine and endocrine pancreata. The endocrine secretes hormones including insulin and glucagon, which regulate blood glucose metabolism. The exocrine pancreas secretes zymogens and active enzymes that, ultimately, aid in digestion. EPI occurs when the part of the pancreas (acinar tissue) that produces digestive enzymes no longer functions properly. As a result, the dog can't digest its food. A progressive loss of pancreatic cells that make digestive enzymes leads to this condition. The most common cause in dogs is the pancreatic acinar atrophy. The atrophy in turn can be caused by previous infections, a blocked pancreatic duct, or genetics.
EPI is a potentially life-threatening condition. Loss of digestive enzymes leads to maldigestion and malabsorption of nutrients. When a dog suffers from EPI, its pancreas fails to produce enough digestive enzymes that are needed for proper digestion of the food. Some of the enzymes are: lipases, to digest fats; amylase, to digest starch/sugars; and proteases, to digest proteins. Even though the dog is eating enough food, and in many cases much more than enough, it is literally starving. Without enzymes to break down the food eaten, nutrients cannot be absorbed and consequently, the body can not utilize unabsorbed food nutrients. The dog becomes weak and skinny and, if proper treatment is not provided, can have fatal consequences.
This condition can occur in any pure or mixed breed dogs but it is a hereditary condition in German Shepherds.
Malabsorption, digestive problems and malnutrition can all lead to an over growth of bacteria in the intestines. Common symptoms associated with EPI include
Weight Loss, despite normal or increased appetite
Frequent or greater volume of stool and gas
Coprophagia, a condition which causes an animal to eat its own stool.