The pancreas is a long, slender organ situated in the upper part of the abdomen attached to the back wall of the abdominal cavity in a dog. The stomach and intestines lie in front of the pancreas. The pancreas is shaped like a fish, having a head, a short neck, body and a tail.
The beginning portion of the small intestine called the duodenum surrounds the head of the pancreas. The body is located behind the stomach and the tail touches the spleen, located at the left upper portion of the abdomen, below the rib cage.
Many major blood vessels like the aorta and the vena cava, as well as nerve trunks pass through or very close to the pancreas.
The glands in the pancreas are covered in a tissue capsule. The exocrine cells of the pancreas secrete important digestive enzymes viz., amylase, pancreatic lipase, chymotrypsinogen, trypsinogen. In addition to this, it is highly important to produce inactive enzymes in the pancreas. If there are any lacunae in the synthesis of these enzymes, there is a possibility of auto-degradation, which finally leads to pancreatitis.
Pancreatic juices will be poured directly into the duodenum through intralobular ducts.
The hormones secreted by the cells in the stomach and duodenum control pancreas exocrine function. The hormones—secretin, cholecystokinin, and gastrin are secreted in lieu with the distension and the presence of the food in the stomach.
The enzymes trypsinogen and chymotrypsin of pancreatic juice will be acted upon by the enterokinase, an enzyme of the intestines. This will activate the trypsinogen to break down to trypsin.
The pancreatic exocrine tissue also helps in neutralizing the stomach acid in the duodenum by secreting bicarbonate. Pancreatitis or diabetes mellitus is the sequel of abnormal pancreatic function.
Exocrine Pancreatic Insufficiency is more prevalent in German Shepard dog (70%), English Setters (5%) and Collies (rough coated) (20%). The main reason for this condition is hereditary (autosomal recessive) and involves immune-mediated damage of the pancreas. Due to this reason, there is possibility of “pancreatic acinar atrophy” (PAA), where the pancreas simply is wrinkled and useless. A lack of effective pancreatic exocrine secretion in the small intestine leads to EPI.
Other probable causes for canine EPI are pancreatic neoplasia, repeated acute or subacute pancreatitis, and chronic pancreatitis.