Duodenal impression

The duodenal impression of the liver is a shallow depression found on the visceral surface of the liver, typically formed by the contact of the liver with the descending duodenum. Its presence, shape, and prominence vary among domestic species due to differences in liver morphology and topography in relation to adjacent organs.

2. Species Variations

• Ruminants (Cattle, Sheep, Goats): In ruminants, the liver is positioned more vertically on the right side due to the large rumen occupying the left. The duodenal impression is located along the caudoventral margin of the caudate process and right lobe. In oxen, the impression is shallow but identifiable. The close anatomical proximity facilitates the formation of the bile duct, which joins the pancreatic duct (in sheep and goats) before entering the duodenum.

• Equine (Horse): In horses, the liver lies more transversely, and the duodenal impression is less prominent. The right lobe may show slight indentation from the descending duodenum. Due to the absence of a gallbladder, the bile duct takes a straight path from the liver to the duodenum, and the impression is not as marked.

• Pigs: The porcine liver shows a well-defined duodenal impression on the right lobe, with the liver largely situated on the right side. The bile duct opens into the duodenum without a gallbladder in some breeds, although most pigs do possess a gallbladder.

• Carnivores (Dog, Cat): The liver in carnivores lies obliquely, and the duodenal impression is typically found on the caudolateral part of the right medial and right lateral lobes. It is more distinct in dogs due to their prominent descending duodenum and the presence of a well-formed gallbladder that lies between the quadrate and right medial lobes.