Haemoparasites—Challenging and Wasting Infections in Small Ruminants: A Review

Abstract

Haemoparasites include bacteria, mycoplasma, protozoa and flagellates inhabiting the bloodstream of living hosts. These infections occur worldwide and are transmitted by vectors, especially ticks and tsetse flies. Geographical distribution varies due to movements of animals and vectors between geographical areas, and even between countries and continents. These changes may be caused by climate change, directly and indirectly, and have a huge effect on the epidemiology of these microbes. Active and ongoing surveillance is necessary to obtain reliable maps concerning the distribution of these infections in order to do proper risk assessment and efficient prophylactic treatment. Genera <i>Anaplasma</i>, <i>Ehrlichia</i>, <i>Mycoplasma</i>, <i>Babesia</i>, <i>Theileria</i> and <i>Trypanosoma</i> include common haemoparasite species in small ruminants causing a variety of clinical manifestations from high fatality rates to more subclinical infections, depending on the species or strain involved. These infections may also cause ill-thift or long-lasting wasting conditions. Life-long infections are a common feature of these pathogens. The present review will focus on haemoparasites in small ruminants, especially related to challenging and wasting infections.