Changes

==Treatment==

==Treatment==

In animals with acquired PSS, the underlying cause should be treated and HE should be managed as described [[Hepatic Encephaolopathy|here]].  Acquired shunts should never be ligated as they occur as a compensatory response to portal hypertension and ligation would increase portal pressure.

In animals with acquired PSS, the underlying cause should be treated and HE should be managed as described [[Hepatic Encephalopathy|here]].  Acquired shunts should never be ligated as they occur as a compensatory response to portal hypertension and ligation would increase portal pressure.

Animals affected by congenital PSS may be managed either medically or surgically but a recent study has shown that those undergoing surgical ligation of the shunting vessel have a longer median survival time.  Medical management is often employed in those animals that show few clinical signs on presentations, are older or which have a shunt that is not amenable to ligation.   

Animals affected by congenital PSS may be managed either medically or surgically but a recent study has shown that those undergoing surgical ligation of the shunting vessel have a longer median survival time.  Medical management is often employed in those animals that show few clinical signs on presentations, are older or which have a shunt that is not amenable to ligation.   

*'''Portal hypertension''', causing ascites, haemorrhagic diarrhoea, septic shock and a painful abdomen.  The abdominal girth is often measured regularly after the surgical procedure to assess the degree of abdominal distension.  Some ascites is to be expected but severe clinical signs warrant a further surgical procedure to loosen the ligature around the shunt.  Ascites should resolve over time but it can be managed with the diuretic spironolactone (because it occurs in part due to inappropriate activation of the renin-angiotensin-aldosterone system).

*'''Portal hypertension''', causing ascites, haemorrhagic diarrhoea, septic shock and a painful abdomen.  The abdominal girth is often measured regularly after the surgical procedure to assess the degree of abdominal distension.  Some ascites is to be expected but severe clinical signs warrant a further surgical procedure to loosen the ligature around the shunt.  Ascites should resolve over time but it can be managed with the diuretic spironolactone (because it occurs in part due to inappropriate activation of the renin-angiotensin-aldosterone system).

*'''Portal vein thrombosis''' because portal blood flow may be drastically reduced.

*'''Portal vein thrombosis''' because portal blood flow may be drastically reduced.

*'''Seizures''' or '''status epilepticus''', particularly in small breeds of dog.  Seizures occur most commonly 1-3 days after ligation and probably result from rebalancing of neurotransmitter levels in the CNS.  Long-term anticonvulsant therapy may be required and some animals may acquire permanent defects, such as blindness.  

*'''Seizures''' or '''status epilepticus''', particularly in small breeds of dog.  Seizures occur most commonly 1-3 days after ligation and probably result from rebalancing of neurotransmitter levels in the CNS.  Long-term anticonvulsant therapy may be required and some animals may acquire permanent defects, such as blindness.

==Prognosis==

==Prognosis==