ULTRASONOGRAPHIC DIAGNOSIS OF CONGENITAL PORTOSYSTEMIC SHUNT IN 14 CATS

Twenty-four cats with clinical and, or, clinicopathological signs comp atible with portosystemic shunting were examined prospectively using t wo-dimensional grey-scale, duplex and colour-flow Doppler ultrasonogra phy. Diagnosis of congenital portosystemic shunt was subsequently conf irmed in 14 cats using operative mesenteric portography and surgery. O f the 14 affected cats, nine were purebred; eight were male and six fe male. The mean age at the time of diagnosis was nine months (range fou r to 27 months). Ultrasonographic evidence of a small liver was presen t in seven cats (50 per cent); visibility of intrahepatic portal vesse ls was reduced in three (21 per cent). An anomalous blood vessel was i dentified ultrasonographically in each cat; in 10 cats (71 per cent) t he vessel was observed to originate from the portal vein and drain int o the caudal vena cava. Abnormally variable portal blood flow was pres ent in eight of the 10 cats in which it was measured. At surgery, six shunts were intrahepatic and eight extrahepatic; the ultrasonographic diagnosis of intra- versus extrahepatic shunt was correct in 13 cats ( 93 per cent). No anomalous blood vessels or abnormalities affecting th e portal vein were detected ultrasonographically in any of the 10 cats that did not have congenital portosystemic shunting. Hence, the accur acy of ultrasonography for diagnosis of congenital portosystemic shunt ing in this series was 100 per cent.