Acquired portosystemic shunts secondary to hepatic microvascular dysplasia in a young dog

Abstract

A one year old spayed female Bichon Frise dog presented with gait abnormalities and seizure. Serum biochemical results showed elevated levels of alkaline phosphatase, alanine aminotransferase, and ammonia. Serum bile acid level was also increased to be over 30 mol/L on preprandial. Urinalysis identified the presence of ammonium urate crystal. Abdominal ultrasonography and CT revealed aberrant, tortuous, and multiple small vessels connected to the caudal vena cava between left kidney and caudal vena cava. Macroscopic specific findings associated with extrahepatic congenital portosystemic shunts (PSS) or other liver diseases were not identified. Liver biopsy was performed. Histopathologic evaluation revealed hepatic lobular hypoplasia with portal arterial duplication and vascular shunts. Based on these finding, this case was diagnosed as multiple acquired PSS secondary to hepatic microvascular dysplasia (HMD) and hepatic encephalopathy. A liver biopsy is recommended to differentiate HMD from other liver diseases and to confirm HMD when a young dog has multiple acquired PSS. ? 2020, Korean Society of Veterinary Clinics. All rights reserved.