liver flukeparasitic flatworm of cattle and other grazing anim

animals biology cattle dendriticum dicrocelium disease fish flat flatworm fluke freshwater goat grazing hog human intestinal invertebrate lancet liver livestock medical medicine microphotography microscope parasite parasitic parasitology photomicrography pig platyhelminth platyhelminthes pond snail trematoda trematode uncooked veterinarian worm zoology