CONGENITAL INTERRUPTION OF THE PORTAL-VEIN AND CAUDAL VENA-CAVA IN DOGS - 6 CASE-REPORTS AND A REVIEW OF THE LITERATURE

Objective-To describe six dogs with congenital abnormalities involving the portal vein, caudal vena cava, or both. Animals-Six client-owned dogs with congenital interruption of the portal vein or the caudal ven a cava, or both. Methods-Portal vein and caudal vena cava anatomy was evaluated by contrast radiography and visualization at surgery. Vascul ar casts or plastinated specimens were obtained in three animals. Resu lts-Portal blood shunted into the caudal vena cava in four dogs and th e left hepatic vein in one. Two of these five dogs also had interrupti on of the caudal vena cava with continuation as azygous vein, as did a n additional dog, in which the portal vein was normally formed. Portal vein interruption was present in 5 of 74 (6.8%) dogs with congenital portosystemic shunts evaluated at the Veterinary Teaching Hospital dur ing the study period. Conclusions-Serious malformations of the abdomin al veins were present in more than 1 in 20 dogs with single congenital portosystemic shunts. Clinical Relevance-Veterinarians involved in di agnosis and surgery for portosystemic shunts should be aware of these potential malformations, and portal vein continuity should be evaluate d in all dogs before attempting shunt attenuation. (C) Copyright 1998 by The American College of Veterinary Surgeons.