Anomalous vascular connections between the portal and systemic circulations can result in several profound alterations in normal physiology. In most cases the presenting clinical signs are referable to the nervous, gastrointestinal, and urinary systems. Medical management may help control the clinical signs, but only surgical redirection of the shunting blood back to the liver parenchyma can result in reversal of the hepatic atrophy and dysfunction that exists. This article describes the problems associated with the diagnostic, medical, and surgical management of animals with congenital portosystemic shunts.