Abstract
This is the case of a 7-year-old, spayed beagle weighing 8 kg that was admitted for self-injurious behavior of tail chasing. This behavior worsened after the earthquake. Based on the results of various tests, impairment of hepatic function due to hypoplasia of the portal vein was diagnosed. Preferential management of hepatic function disorder resulted in a decrease in the self-injurious behavior.