Computed tomographic features of segmental aplasia of the caudal vena cava, portocaval shunt and Situs ambiguous in two dogs.

A 3-year-old crossbreed dog (case 1) and a 3-month-old German Shorthaired Pointer (case 2) were presented for acute signs of encephalopathy. A portosystemic shunt (PSS) was suspected based on clinical context and laboratory exam results and was confirmed on computed tomography (CT) angiography in both cases. A left-sided azygos (case 1) and right-sided azygos (case 2) continuation of an interrupted caudal vena cava (CVC) and a situs ambiguous (SA) were also observed and considered as incidental findings. Both dogs underwent PSS surgical correction. Postsurgical follow-up imaging procedures suggested concomitant primary hypoplasia of the portal vein (PHPV) in both cases.