Khan et al., The J. Anim. Plant Sci. 27(4):2017 1190 RISK FACTORS ASSESSMENT AND MOLECULAR CHARACTERIZATION OF THEILERIA IN SMALL RUMINANTS OF BALOCHISTAN Mir A Khan 1 , M. A. Khan 1 , I. Ahmad 3* , M. S. Khan 1 , A. A. Anjum 2 , A. Z. Durrani 1 , K. Hameed 4 , I. U. Kakar 5 , A.Wajid 6 , M. Ramazan 7 and Rafiuddin 7 1 Department of Clinical Medicine and Surgery, 2 Department of Microbiology, 5 Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan. 3 Department of Veterinary Clinical Sciences, University of the Poonch, Rawalakot, Azad Kashmir , 4 Mirpur University of Science and Technology, Mirpur Azad Kashmir, Pakistan.. 6 Department of Clinical Medicine and Surgery, Lasbella University of Water Agriculture Marine Sciences Uthal, Balochistan, Pakistan. 7 Livestock and Dairy Development Department Balochistan, Pakistan *Corresponding Author email: vetmedicine2015@gmail.com ABSTRACT In Pakistan, theileriosis is an important disease of small ruminants due to favourable climatic conditions for ticks. The northern highlands of Balochistan were never been previously explored for theileriosis, so the present one year study (June 2012-May 2013) was designed to determine epidemiology and molecular characterization of Theileria in domestic small ruminants in two regions (Northern Highlands and Suleiman Mountain) of Balochistan, Pakistan. The domestic small ruminant flocks (n= 2200 sheep; n=670 goats) were visited for data collection and blood sampling. The samples were examined microscopically for the presence of Theileria in RBCs. The association of various risk factors with the disease were tested through Chi square test. The Prevalence of Theileriosis was higher in sheep than goats (20.81% vs 9.70%; p<0.05). We did not find any significant difference in the prevalence of disease in Northern Highlands and Suleiman Mountain Region of Balochistan (p>0.05). A clear trend of seasonal pattern (p<0.05) came to record with highest in summer season (30.30%) followed by autumn (19.07%), spring (14.52%) and winter (7.61%). The disease was significantly higher (p<0.05) in above two years age group (22.17%) followed by between 1-2years (15.85%) and lowest in less than one year (7.99%). Gender was not a significant risk factors for theileriosis (18.92% male vs 17.92% female; p>0.05). The molecular characterization of positive samples through 18S ribosomal RNA revealed the presence of Theileria lestoquardi and Theileria ovis in the infected animals. T. lestoquardi was dominated in both sheep (73.80%) and goats (69.23%) while T. Ovis accounted for only 26.19% of sheep infection and 30.76% in goats.The observed prevalence can be explained by the farming system of the rural livestock of Balochistan, lack of awareness of community, absence of diagnostic facilities, expensive acaricidal drugs and poor economic condition of farmers. Key words: Theileriosis, T. lestoquardi, T. ovis, Balochistan, Small ruminants INTRODUCTION Theileriosis is a tick borne parasitic infection responsible for heavy economic losses to livestock industry due to high morbidity and mortality associated with it (Schnittger et al. 2000; Naz et al. 2012). There are several species of genus Theileria (T. lestoquardi, T. ovis, T. separate and newly identified T. china1) which vary in their virulence reported to cause theileriosis in small ruminants (Chaeet al. 1999; Li et al. 2014). The disease is characterized with fever, weakness, anorexia, conjunctivalpetechae, swollen lymph nodes, anaemia and cough. The animals are also seen with nasal and ocular discharges, pyexia, leucopenia, paleness of mucus membrane (Naz et al. 2012). The diseased animals may die within 3-4 weeks after getting lymphocytolysis if left untreated (Ahmed et al. 2015). The later stages of the disease are associated with diarrhea, dysentery, recumbency and increase risk for viral, bacterial and fungal infections. (Schnittger et al. 2000; Ahmed et al. 2015). Malignant Ovine theileriosis caused mostly by T. lestoquardi is considered one of the major constraints to domestic small ruminant industry of the tropical and sub- tropical countries where environmental factors are suitable for ticks (El-Azazy et al. 2001; Saeed et al. 2015;Razmietal. 2006;Sayinet al. 2009;Durraniet al. 2011; Jabbar et al. 2015). Theileriosis is diagnosed primarily on the basis of history of signs and symptoms followed by microscopic examinations of blood smears for the detection of parasites (Kirvar et al. 1998; Durrani et al. 2011). However, microscopy is not reliable in detection of carrier animals and piroplasm differentiation of Theileria species due to morphological similarities (Aktas et al. 2006). The development of advanced PCR based assay is considered as highly sensitive and specific for the detection of species of Theileria (Aktas et al. 2006; Durrani et al. 2011). In Pakistan, theileriosis has been reported from small ruminants but never been extensively explored on large scale for prominent risk factors for the disease The Journal of Animal & Plant Sciences, 27(4): 2017, Page: 1190-1196 ISSN: 1018-7081