cerebrospinal nematodiasis of cattle, sheep and goats in iran

background: the prevalence of setariasis in cattle and cerebrospinal nematodiasis in sheep and goats were determined in two geographical regions of iran. methods: in two provinces of iran: mazandaran (zone i) and qazvine (zoneii)   where sheep and goats were suffering from symptoms similar to cerebrospinal nematodiasis, the peritoneal cavities of  763 and 1020 cattle were searched for adult setaria sp. respectively. history taking of 4770 sheep from zone i and 25550 sheep and 3190 goats from zone ii were per­formed for the presence and determination of cerebrospinal nematodiasis in sheep and goats. to study pathological changes induced in central nervous system 7 sheep from zone i and 4 sheep and 2 goats from zone ii with symptoms similar to csn were necropsied. results: our findings revealed that 47% and 13.2% of cattle in zone i and ii harboured setaria digitata (99.45%) and s. digitata (67.12%) plus s.labiato-papillosa (17.46%) respectively. history taking showed that each year 2.53% of sheep in zone i and 1.65% of sheep and 1.25% of goats in some districts of zone ii (e.g. roudbar alamout)  suffered from symp­toms similar to cerebrospinal nematodiasis the main clinical signs of which were difficulty in hind limbs movement (lumbar paralysis). at necropsy, no lesions were observed macroscopically in the brains as well as spinal cords. but in a few cases, central nervous system were congested  and edematous .histopathological examination of cns of necropsied animals showed mild leptomeningitis and eosinophilic and lymphacytic encephalomyelitis with numerous hemorrhagic tracts, degeneration and necrosis due to migration of the larvae. the cross section of nematode larvae was observed in the brain section of a sheep in zone i. conclusion: the results of this study showed that setariasis of cattle is very prevalent in both region mainly in zone i and sheep and goats harbor low percentage of csn but with marked pathological lesions.