The pancreas has two main functions: 1) exocrine - to produce the enzymes needed to digest food, and 2) endocrine - to produce hormones, including the hormone insulin, which facilitates the uptake and storage of glucose (sugar) and amino acids (proteins).
The pancreas secretes several digestive enzymes (exocrine function), and the principle job of these enzymes is to digest fats and proteins in the food. If this portion of the pancreas is inflamed, a condition called Pancreatitis results; the compromised tissue releases these enzymes from the ducts and begin to "autodigest" the tissue. This may lead to intense abdominal pain, vomiting and diarrhea. There are many possible causes, though in many cases, the cause remains unknown.
If, due to repeated bouts of pancreatitis or congenital malfunction, the pancreas fails to make enough of the digestive enzymes, a condition called pancreatic insufficiency results. This condition results in a malabsorbtion of fats and proteins from the food, leading to chronic weight loss, poor hair coat, and diarrhea in affected animals. Understandably, the animal is often hungry and may eat odd items in search of food.
If the endocrine function of the pancreas does not work properly, a condition called diabetes may result. Without the necessary amounts of insulin produced by the pancreas, the body is unable to utilize the necessary glucose (sugar) from the food nor effectively regulate glucose levels in the body. Without insulin, glucose stays in the bloodstream, unable to reach the cells (where it is needed for energy and "food" for cells), and is eventually released from the body via the urine (glucose overload).
The pancreas is a complex organ, and vital for digestion and sugar control. If your animal has a painful abdomen, vomiting, diarrhea, or loss of appetite, please seek veterinary attention immediately.