372 1994-2018 All Rights Reserved. Online Journal of Veterinary Research. You may not store these pages in any form except for your own personal use. All other usage or distribution is illegal under international copyright treaties. Permission to use any of these pages in any other way besides the before mentioned must be gained in writing from the publisher. This article is exclusively copyrighted in its entirety to OJVR publications. This article may be copied once but may not be, reproduced or re-transmitted without the express permission of the editors. OJVRTM Online Journal of Veterinary Research© Volume 22 (4):273-280, 2018. Prevalence of Theileria equi in horses in central Iraq determined by microscopy and PCR. Hayder Dawood Saleem, Firas Rashad Al-Samarai Department of Veterinary Public Health/College of Veterinary Medicine/University of Baghdad/Iraq Saleem HD, Al-Samarai FR., Prevalence of Theileria equi in horses in central Iraq determined by microscopy and PCR. Onl J Vet Res., 22 (4):273-280, 2018. We report incidence of Theileria equi in 94 horses from 7 locations in Iraq during March to May 2017. Differences in prevalence between countries are attributed to sample size, method of detection, breed and/or climate. Infected horses can appear healthy but still be carriers being a continuous source of infection. Blood samples were subjected to slide stain for microscopy and real-time PCR (RT-PCR) of a 450bp long section of 18S rRNA. We found that T. equi was present in all locations in central Iraq. By microscopy we found ~20% and by RT-PCR, 32% prevalence. Incidence was much higher (~64%) in Baghdad. For microscopy, sensitivity was ~30% and specificity 84.4%. Differences in prevalence due to location and activity (of horse) were significant (P<0.0001) but not for gender, age or period of data collection. Risk factors were location and type of horse (draft/sports) (P<0.0001). We find that microscopy is not suitable for detection of T equi in horses and confirm that PCR is more precise. Keywords: Prevalence, Theileria equi, Iraq, RT-PCR, Risk factors. INTRODUCTION Equine babesiosis is a tick-borne protozoal disease which infects all equids and leads to acute anaemia (Friedhoff et al. 1990). The disease is caused by Theileria equi and Babesia caballi and ixodid ticks are vehicles of transmission (Wise et al. 2013). Theileria equi was previously identified as Babesia equi (Mehlhorn et al. 1998) but Uilenberg (2006) and Allsopp et al., (2007) find it between babesia and theileria lineages. Genomic analysis has supported the concept of a new genus for T. (B.) equi