Bluetongue in an adult ewe-A Case Report

Bluetongue (BT) is an infectious, non-contagious, vector-borne viral disease affecting wild and domestic ruminants (Constable et al., 2016). It is caused by the Bluetongue virus (BTV), a member of the Orbivirus genus in the Reoviridae family (Pringle, 1999). Currently, 28 BTV serotypes are recognized, with 23 reported in India. BTV is primarily transmitted by Culicoides midges (Constable et al., 2016). Additional transmission routes, including direct vertical, oral, venereal, and indirect mechanical transmission, have been documented, although their epidemiological significance remains uncertain (Belbis et al., 2017; Darpel et al., 2016; Kirkland et al., 2004).While most animals infected with BTV show no symptoms, a fatal disease has been reported in a proportion of infected sheep, deer, and wild ruminants (Rupner et al., 2021). Sheep are the most susceptible hosts, whereas cattle, buffalo, and goats serve as reservoirs. Infection with virulent strains can result in mortality rates as high as 70%-100% in naïve sheep (Saminathan et al., 2020). BT was first reported in India in 1964 in Maharashtra state (Sapre, 1964). Since then, it has been reported in several states and union territories, becoming endemic in the country. Serological evidence exists in large and small ruminants across various states. BT causes significant economic losses due to morbidity, mortality, treatment costs, and trade restrictions in outbreak-prone areas, making it a notifiable disease to the World Organization for Animal Health (OIE)