Investigations regarding on the clinical expression of Bluetongue virus infection of domestic ruminants in the South-East region of Romania

Abstract

Bluethonge has a significant economic impact, mainly due to the effect of the disease on animals (morbidity, mortality, reproductive insufficiency, reducced of milk production and animal weakening) and, in particular, disruption of international trade in animals and animal products. In the South-East region of Romania, in the period 2014-2017, animals with clinical signs specific to Bluetongue virus were identified.1437 domestic ruminants with a suspected disease were examined. Of these, 418 (29,08%) had clinical features similar to those of Bluetongue. The incidence of clinical signs in animals with suspected disease varied by species. Thus, the clinical aspects were present in 22,21% cattle, 68,21% sheep and 1,54% goats. Following clinical examination, the simultaneous presence of several clinical signs specific for Bluetongue virus infection was observed in cattle and sheep. In cattle, the incidence of clinical signs was variable, most frequently reported conjunctival mucosal hyperemia, epiphora, sialorrhea, gingival ulceration, swelling and cyanosis of the tongue, nasal edema with ulcerations of the nasal mucosa and muco-purulent jet, circumcised necrosis at the level of the udder, accentuated weakening, congestion of the coronary area, torticollis, digestive disorders, exongulations and inability to move. The pathogenesis of Bluetongue is similar in cattle and sheep, so that the clinical evolution was similar in the two species. In goats, the disease evolved inapparently or with diminished clinical expressions: prostate condition, mucopurulent discharge, edema and nasal ulcers, cyanosis of the mucous membranes, curls and limping. In addition to the immediate losses, the onset of the disease can generate long-term effects, which can decisively affect the Romanian animal breeding sector. The ease with which the Bluetongue disease has spread, shows that the territory of Romania is affected by climate change caused by global warming, which allowed the transmitting vectors to proliferate and spread the Bluetongue virus to the receptive animals.