High Quality Content by WIKIPEDIA articles! Exocrine pancreatic insufficiency (EPI) is the inability to properly digest food due to a lack of digestive enzymes made by the pancreas. This disease is found frequently in dogs. EPI is also found in humans afflicted with cystic fibrosis and Shwachman-Diamond Syndrome. EPI is caused by a progressive loss of the pancreatic cells that make digestive enzymes. Most commonly in dogs, this is caused by pancreatic acinar atrophy. The atrophy in turn can be caused by previous infections, a blocked pancreatic duct, or genetics. Chronic pancreatitis is the most common cause of EPI in humans and cats, but it is an uncommon cause in dogs. Loss of digestive enzymes leads to maldigestion and malabsorption of nutrients.