Abstract — A 2-year-old boxer dog from southern Ontario was evaluated because of acute onset lethargy.
Exploratory laparotomy revealed a hemorrhagic, destructive, liver mass. Histology, immunohistochemistry, and
polymerase chain reaction confirmed Echinococcus multilocularis as the cause of the hepatic mass. This constitutes
the first description of endemic E. multilocularis in Ontario.