j davoodi - Department of Parasitology, Islamic Azad University, Abhar Branch, Abhar – Iran.

Nematode Setaria belongs to Spirurida order and Setariidae family. The adult worms live in abdominal cavity freely (without clinical signs) and their sheathed microfiller exist in blood of theirdefinitive hosts. Microfillers lead to cerebrospinal Nematodiosis and lumbar paralysis in non-specific hosts. During a year we inspected468 slaughtered cow and water buffalo from slaughter house of Meyaneh in East Azerbaijan province of Iranlooking for adult SetariaSpp.and either collected 209 blood samplesof them and 120 blood samples of alive native cow were collected too in order to findingmicrofiller infection. Adult worms were examined by light microscope and blood samples were examined with Knott method inParasitology Laboratory of Veterinary Faculty of Tehran University.52(11.11%) slaughtered cases were infected by adult worms.2.87% and 4.16% blood samples of slaughtered cases and alive cows were infected by microfiller respectively. Maximum infection was in winter and minimum infection was in autumn. It was the first survey thathad been done in East Azerbaijan province and has shown that humidity and temperature have direct effect on activation ofmosquitos as intermediate hosts and incidence of setariosis subsequently and setariosis exist in this area however the rate of infection are low.

Setariosis , Miyaneh , Ruminant