The pancreas of domestic animals was an example for exo and endocrine gland. It is a soft, encapsulated, lobulated gland and covered by a thick connective tissue capsule in buffalo and pig. The capsule was made up of predominantly dense irregular collagen fibres, few reticular and elastic fibres and blood vessels while capsule of pig consisted of adipose tissue in addition to connective tissue fibres. The average thickness of capsule was 30.05 to 98.62 µm in buffalo, 20.27 to 44.10 µm in pig, 18.20 to 25.64 µm in sheep, 20.27 to 44.10 µm in goat and 13.28 to 40.10 µm in dog.
The acini were round to oval in buffalo and sheep, but in goat, dog and pig the acini were in variable shapes i.e round, oval, irregular and few elongated in shape. The average diameter of the acini in buffalo was 20 to 60 µm, 20 to 40 µm in sheep, 20 to 40 µm in goat, 20 to 30 µm in dog and 35 to 50 µm in pigs. Each acinar cell possessed distinct basal zone and an apical zone in buffalo, sheep, goat, dog and pig. The presence of two or three centroacinar cells were noted in the lumen of the acini in sheep, goat, dog and pig but only single centroacinar cell was noted in buffalo. The distinct periacinar and periductal nerve plexus were observed in buffalo, sheep, goat, dog and pig and many neurons were also observed as isolated cells and they aggregated to form small and large ganglia (pancreatic ganglia) in buffalo, sheep and goat between the acini close to the islets in pancreas. These ganglia consisted of large multipolar neurons possessed eccentric nucleus and were surrounded by collagen and reticular fibres and the duct system of the exocrine pancreas consisted of small, medium and large ducts i.e intercalated, intralobular and interlobular ducts respectively in buffalo, sheep, goat, dog and pig.