Presentation,stabilisation and contrast-enhanced computed tomographic (CT) diagnosis of a left gastrocaval portosystemic shunt in a pony foal

A 2-week-old pony foal was presented for recurrence of neurological dysfunction, obtunded-comatose mentation and collapse. Signalment, history, haematological and clinical chemical measurements and response to treatment prompted a presumptive diagnosis of hepatic encephalopathy secondary to a portosystemic shunt. This case differs from previous reported cases of  congenital portosystemic shunts in horses due to the early onset of clinical signs, which usually occur at 2–6 months of age. In addition, in comparison with previously reported cases, this foal stabilised rapidly with minimal intervention. Contrast-enhanced computed tomography (CT) confirmed a left gastrocaval extrahepatic portosystemic shunt. Surgical intervention was not attempted due to financial constraints, so the foal was subjected to euthanasia, and on post-mortem examination, the anomalous vascular connection could clearly be identified.