The v. portae of the domestic cat and variability of its tributaries.

In the domestic cat the v. portae originates as a thick venous trunk below the liver through confluence of the v. gastrica sinistra, v. lienalis and v. mesenterica cranialis. It was formed in this way in 19 cases, i.e. in 63.3%. Among the aberrations found in the other cases, the most frequent was a common trunk for the v. gastrica sinistra and v. lienalis (6.7%). In 26 cases (86.6%), the v. gastrica sinistra was an independent tributary of the v. portae. A single v. lienalis was found in 27 cases (90.0%). Inter-organ anastomoses were found in the region of the v. lienalis. In 29 cases (96.7%) they connected the cranial part of the spleen with the fundus ventriculi. Inter-organ venous anastomoses between the caudal part of the spleen and the pancreas were found in four cases (13.4%). These anastomoses came from within the spleen and joined the veins of the stomach or the pancreas. In 14 cases (46.6%) the v. mesenterica cranialis originated as the v. colica dextra or v. caecalis. In nine cases (30.0%), in the concavity of the small intestine we found two trunks forming the v. mesenterica cranialis-one from the caecum and the other from the ileum and jejunum. Lastly, in five cases (16.7%) the v. mesenterica cranialis started only from the ileum and jejunum. The most frequent first tributary-in 19 cases (63.3%)-was a venous trunk of varying length formed by union of the v. mesenterica caudalis and the v. colica media, which started in 11 cases (36.7%) as the v. colica dextra.(ABSTRACT TRUNCATED AT 250 WORDS)