Portosystemic shunts in 3 Dogs with respiratory sign of cough and with dementia signs characterized by hypersensitivity, salivation, and seizure were diagnosed at veterinary teaching hospital of Seoul National University. In radiographs, microhepatica was observed. In abdominal ultrasonography, abnormal intrahepatic connections between the portal vein and the systemic vessels and tortuous vascularity were found. There was no complication such as ammonium urate urolith in kidney or urinary bladder, These dogs were treated with medicine and protein-restricted diet.