Overview
The pancreas produces pancreatic juice, which drains into the duodenum, and, in the islets of Langerhans, insulin and glucagon. In the horse the exocrine secretion is continuous and abundant, rich in bicarbonate and relatively poor in enzymes, matching an almost constant food intake and the role of the large intestine in fibre digestion.
Topography and parts
- Position: on the roof of the abdomen, ventral to the last thoracic and first lumbar vertebrae, between the liver, stomach, duodenum, base of the caecum, right dorsal colon and right kidney.
- Body: the middle part, next to the curve of the duodenum. The portal vein passes through it via the pancreatic ring (anulus pancreatis), an arrangement typical of the horse.
- Left lobe: extends towards the spleen, the stomach and the left kidney.
- Right lobe: follows the descending duodenum and rests on the base of the caecum and the right kidney.
- Ducts: the pancreatic duct opens with the bile duct on the major duodenal papilla and the accessory pancreatic duct opens opposite, on the minor duodenal papilla.
Clinical relevance
- Pancreatic disease is uncommon: acute pancreatitis is rare in horses; it causes colic, nasogastric reflux and shock and is hard to tell apart from proximal duodenitis-jejunitis without surgery or necropsy.
- Neoplasia: pancreatic adenocarcinoma is rare, with weight loss and sometimes ascites.
- Diabetes mellitus: also rare. The insulin dysregulation of equine metabolic syndrome, linked to laminitis, depends mainly on peripheral tissues rather than on pancreatic failure.
- Examination: its deep dorsal position prevents palpation, and it is barely visible on transabdominal ultrasound.