Ventral border

The ventral border of the liver in domestic animals (also referred to as the caudal or inferior border in human anatomical terminology, though "ventral" is more accurate in quadrupeds) is the free margin of the liver opposite the diaphragmatic (dorsal) surface. It is generally thin and sharp, particularly in carnivores and ruminants, and forms the lower margin of the organ as it lies in the cranial part of the abdominal cavity.

This border separates the parietal diaphragmaticsurface from the visceral surface and is often marked by notable anatomical landmarks including:

• Fissures and notches: These include the fissure for the round ligament (ligamentum teres hepatis), which is a remnant of the fetal umbilical vein. This ligament courses along the ventral border.

• Attachment sites: The round ligament attaches at this border, and the falciform ligament may also have a point of attachment near this region.

2. Species-Specific Features

• In the dog: The ventral border is sharp and often marked by the round ligament. The liver is divided into six lobes, and the ventral margin corresponds mainly with the left and quadrate lobes.

• In the horse: The liver is relatively small and asymmetrical. The ventral border is relatively thick and less sharply defined due to the absence of a gallbladder and reduced lobulation. The round ligament is present.

• In ruminants (cattle, sheep, goats): The liver is situated almost entirely on the right side due to rumen displacement. The ventral border is sharp and houses the round ligament. In cattle, the lobation is more prominent.

• In pigs: The liver is large and lies across the midline. The ventral border includes the round ligament and may show prominent notches between the lobes due to distinct lobulation.

• In the cat: Similar to the dog, with a relatively sharp ventral border. The gallbladder is located near the ventral border, especially visible on the visceral surface between the quadrate and right medial lobes.