Materials and Methods: 6 donkeys (3-females, 3-males) were used as the material. After opening the abdominal cavity of the donkeys, whole blood was drained under general anesthesia, it was reached to liver. Portal vein was washed with saltwater 0.9%, and colored latex was injected to it. The livers, kept in the tap water for 48 hours, were dissectioned.

Results: In this study, it was detected that the portal vein brought the 6-stout (mean: 5.75 mm) and 2-slim (mean: 1.57 mm) branches before it produced the ramus dexter. It was determined that the 6-stout branches progressed in the caudal, cranio-dorsal, right caudo-dorsal, right intermediate, right cranio-dorsal and right cranio-ventral directions in the right lobe of the liver. It was identified that other slim two branches spreaded in regional liver tissue. It was detected that the ramus dexter with the somewhat large diamater (mean: 11.32 mm) was divided into two branches as the right caudo-ventral and quadrate lobe directions. It was set that the ramus sinister supplied blood with 7-branches, with average thickness 4.84 mm, to the quadrate and left lobe of the liver. These branches coursed to the left cranio-dorsal, left medial, quadrate lobe (2), left intermediate, left caudo-ventral and left cranio-ventral directions.

Conclusions: Although the intrahepatic ramifications of the portal vein of the horse and donkey were mostly similar to each other, some differences existed with regard to conformation of vessels.