A case of congenital splenophrenic portosystemic shunt in a one year old intact female Shih Tzu

Abstract

A one year old intact female Shih tzu was referred for a suspected portosystemic shunt after increased liver enzymes were discovered during an elective ovariohysterectomy preoperative assessment. Surgery was postponed and the dog was referred for ultrasonographic imaging; findings were suggestive of a single congenital extrahepatic portosystemic shunt. Upon referral to the internal medicine service at Cornell, physical examination disclosed a BCS of 4/9 and retained deciduous teeth. History of intermittent diarrhea and “bilious” vomiting was described and occurrence of neuroencephalopathic signs was denied. Diagnostic clinicopathologic assessments and Computed Tomography (CT) with angiography were completed. The hemogram was unremarkable. The biochemical profile disclosed increased activities of ALT and GGT, and increased concentration of serum bile acids. A Protein C (PC) activity was within normal limits. The CT angiogram disclosed a splenophrenic shunt, a liver judged to be of normal size, and portal venous branches perfusing the right and left liver lobes. Short term medical treatment was provided and shunt ligation surgery was scheduled in a month. Ovariohysterectomy and surgical ligation of the portosystemic shunt were completed without complications. Intra-operative pre- and post-ligation portogram were performed confirming complete ligation of the anomalous vasculature and normal hepatic portal venous perfusion. A liver biopsy submitted for histopathology, aerobic and anaerobic bacterial culture, and metal quantification disclosed changes consistent with portal hypoperfusion, typical of congenital portosystemic shunting. Mild copper accumulation in zone 3 hepatocytes was also described. Two bacterial organisms were grown from the liver cultures: an E. coli and Streptococcus sp. Presence of eosinophils in left liver lobe portal tracts and positive bacterial cultures suggested a possible showering of the liver from the gastrointestinal tract secondary to concurrent bowel inflammation. Unfortunately, there was no suspicion of enteric inflammation at the time of surgery and the intestines were not biopsied. An antibiotic (Cephalexin) was prescribed to treat the confirmed bacterial infection. On re-evaluation one month after shunt ligation, episodic vomiting and diarrhea had resolved and all liver enzymes had returned to the normal reference range.