Paramphistomum is a genus of parasitic flat worm belonging to the digenetic trematodes. It includes tiny flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for a serious disease called paramphistomiasis (or classically amphistomosis), especially in cattle and sheep. Its symptoms include profuse diarrhoea, anaemia, lethargy, and often result in death if untreated. They are found throughout the world, and most abundantly in livestock farming regions such as Australia, Asia, Africa, Eastern Europe, and Russia.