Clinicopathological and Molecular Studies on Ovine Theileriosis in Egypt

Abstract

The aim of this study was to survey the prevalence of ovine theileriosis in certain areas of Egypt (Bahtim, Marg, Al Oubour, Kafr Tohormous, Faisal, Al-Saff, and Badr center), and to demonstrate the hematological, biochemical and pathological changes during Theileria infection with the identification of Theileria species by molecular techniques such as PCR, sequencing and phylogenetic analysis. A total of 152 sheep (from April 2018 to February 2019) were subjected to general examination and sampling. The animals were randomly selected from farms and veterinary clinics. According to PCR result, the animals were divided into 3 groups: negative group (96 sheep), T. ovis infected group (30 sheep) and mixed T. ovis and T. lestoquardi group (26 sheep). The clinical examination of infected sheep revealed that the mostly observed clinical signs of the disease were pyrexia, cachexia, emaciation, lacrimation, conjunctivitis, pale mucous membrane and tick bite wounds. By microscopic examination of blood smears, the incidence Theileria infection was 33 out of 152 samples (21.7%) while its incidence by using PCR (universal Theileria spp. Primer) was 56 out of 152 (36.8%) of examined animals. During the microscopic examination of blood smear, intracellular pleomorphic (round, oval, rod and comma) piroplasms were detected. Evaluation of the hematological parameters showed macrocytic hypochromic anemia with significant leukopenia, neutropenia, lymphopenia, monocytopenia, eosinopenia and thrombocytopenia in the infected groups compared with Theileria negative group.