Veins of the large intestine, stomach and pancreas of the domestic cat and their variability.

Most frequently - in 19 cases (63.3%) - the v. colica media was a tributary of a trunk, formed together with the v. mesenterica caudalis, which emptied into the v. mesenterica cranialis. In two cases (6.7%) it emptied independently into the v. mesenterica cranialis. In 25 cases (83.3%) the v. mesenterica caudalis arose from the rectum and, at colon ascendens level, acquired one or more vv. colicae sinistrae. In six cases (19.8%) the v. colica dextra opened into the v. ileocolica and in eight cases (26.7%) it was the initial tributary of an independent v. ileocolica which joined the v. mesenterica cranialis directly. The drainage of venous blood from the stomach is organized as follows: the fundus region is connected to the v. lienalis by means of inter-organ anastomoses. The curvatura minor is drained by means of the v. gastrica sinistra. Venous blood from the region of the curvatura major ventriculi flows partly into the v. lienalis (by way of the vv. gastroepiploicae or small veins) and partly into the v. gastrica sinistra. Drainage of venous blood from the pancreas: a v. pancreaticoduodenalis cranialis was present in 16 cases (53.3%) and a typical v. pancreaticoduodenalis caudalis was found in 12 cases (40.0%). Simultaneous formation of both vv. pancreaticoduodenalis, with a possible incidence of small venous efferents to the v. lienalis, was observed in only nine cases (30.0%). In 21 cases (70%), blood from the region of the flexura duodenojejunalis was drained by the last v. jejunalis; in other cases it drained into the vv. pancreaticoduodenales.(ABSTRACT TRUNCATED AT 250 WORDS)