Fascioloidiasis: Infection of cattle and other herbivores with the giant liver fluke Fascioloides magna. It is characterized by extensive destruction of the liver parenchyma.

  Fascioloides magna: Fascioloides magna, also known as giant liver fluke, large American liver fluke or deer fluke, is an important parasite of a variety of wild and domestic ruminants in North America and Europe. Adult flukes occur in the liver of the definitive host and feed on blood.