Diameter of the shunt vessel in dogs with incidental extrahepatic portosystemic shunts.

Clinical signs of extrahepatic portosystemic shunts (EHPSS) depend on the amount of blood shunted. In this study, dogs with EHPSS without noticeable clinical signs including 34 left gastro-phrenic, 3 left gastro-azygos and 2 left spleno-gonadal shunts were evaluated. In dogs with EHPSS without noticeable clinical signs, the median maximum diameter of the shunt vessel was significantly smaller compared to PV (p < 0.005). Whenever the diameter of the EHPSS is small in relation to the diameter of the PV, it seems likely that no obvious clinical signs of EHPSS are observed by the owners.