Tick-borne diseases in sheep and goats: Clinical and diagnostic aspects

Tick-borne diseases affect small ruminants in tropical and subtropical regions. In sheep and goats, these diseases are not well characterized although breeding of these species is the main livestock resource in some regions. Ticks transmit viruses (tick-borne encephalitis, Thogoto virus), bacteria (Rickettsiales, Borrelia, Francisella) and protozoa (Babesia and Theileria) to small ruminants some of which cause also zoonotic diseases (e.g. Crimean Congo Haemorrhagic Fever virus, Coxiella burnetti, Anaplasma phagocytophilum). The aim of the paper is to provide an overview of the main diseases due to pathogens belonging to genera Anaplasma, Babesia and Theileria in small ruminants. The authors also report the results of surveys on small ruminants for anaplasmosis and piroplasmosis. Anaplasma ovis is the main etiological agent of anaplasmosis with a prevalence of 82.9% for sheep and 74.9% for goats, prevalences for Anaplasma phagocytophilum were, respectively, 11.9% and 15.2%. Protozoa were present with lower prevalences and the species present were not very virulent, the higher prevalence found was for Theileria ovis 17.7% for sheep and 1.6% for goats. The characterization of these pathogens is important to develop effective control measures to prevent diseases in animals and humans and improve animal well-being and production. (c) 2012 Elsevier B.V. All rights reserved.