Setaria cervi is a species of parasitic roundworm belonging to the genus Setaria. It infects cattle, bison, yak, reindeer, buffalo, moose, and sheep all over the world. It is most prevalent in Europe and Asia. Different species of Aedes mosquito can transmit the filarial worm. Stable fly Haematobia stimulans is the major vector. The mature roundworms are primarily present in the abdominal (peritoneal) cavity, but are capable of migrating to central nervous system causing serious neurological disease.