Hepatic encephalophthy was diagnosed with serum chemistry, abdominal radiography and ultrasonography in a 2.6kg, 4 year-old maltese dog showing signs of hypersalivation, involutary spasm of facial muscles, ataxia, behavior abnormalities like dullness, sleep disorder, restlessness. In serum chemistry, the level of alanine transferase and aspartate trasferase was mildly elevated, ammonia was severely increased. On abdominal radio-graphs, the size of liver was mildly decreased. In ultrasonographic examination, diffuse lesion with hyperechoic change and decreased vasculature were seen in the hepatic region. But vascular abnormalities of liver were not observed. Drug and dietary therapy were undertaken and severities of clinical sign were alleviated.