Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 4 3 2009 09 15 40 51 N Salehi H Haddadzadeh J Ashrafihelan P Shayan A Sadrebazzaz 2015 10 03 Background: The objective of the study was to evaluate the presence of Neospora caninum organisms in the brain of aborted fetuses and placentas of full-term calves born of seropositive cows. Methods: During 2006-2007, 12 brains of aborted calves from Neospora seropositive cattle and 7 pla­centas from seropositive dams giving birth to full-term calves, from four dairy cattle farms located around Tehran province, Iran were examined by Nested-PCR and histopathology techniques. Result: The Nested-PCR demonstrated that all of 12 aborted fetal brain samples and 5 of 7 placentas were infected by N. caninum. Mild to severe placentitis was observed in 5 placentas. Severe hyperemia and pe­rivascular and perineuronal edema revealed in all fetal brain. In 3 out of 12 brains, scattered foci of he­morrhages, neuropilar necrosis and gliosis were present. In addition, nonpurulent encephalitis with severe lymphohistiocytic perivascular cuffing in one case and a small tissue cyst like Neospora caninum cyst in other calf were observed.  Conclusion: Our results confirmed the molecular and histopathologic findings of other studies about Neos­pora caninum infection and it seems to support the hypothesis that Neospora infection is associated with bovine abortion in Iran. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/107 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/107/106