Extrahepatic porto-systemic shunt (PSS) in small animals can be congenital (CPSS) or acquired (APSS) as a consequence of portal hypertension (PH), and are distinguished on the bases of their anatomical pattern. A precise morphologic imaging assessment, along with clinical and histopathologic findings, is important for distinguishing patients with PH from those with congenital PSSs, which requir...