liver fluke

…caused by the liver fluke Fasciola hepatica, a small parasitic flatworm that lives in the bile ducts and causes a condition known as liver rot.

Among domestic animals, the sheep liver fluke (Fasciola hepatica) may cause debilitating and fatal epidemics (liver rot) in sheep. These animals become infected by eating metacercariae encysted on grass. Monogenea are common pests on fish in hatcheries and home aquariums.

…include the widely occurring giant liver fluke of cattle (Fasciola hepatica) and the Chinese, or Oriental, liver fluke (Opisthorchis sinensis, or Clonorchis sinensis). F. hepatica causes the highly destructive “liver rot” in sheep and other domestic animals. Man may become infested with this fluke by eating uncooked vegetables.