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 Anaplasma, Ehrlichia, Mycoplasma, Babesia, Theileria and Trypanosoma 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.

Epidemiological Study Related to the First Outbreak of Ovine Anaplasmosis in Spain

“…The main biological vectors of anaplasmosis are ticks, mainly of the genera Rhipicephalus (R. bursa and R. turanicus), Dermacentor (D. silvarum, D. marginatus and D. andersoni), Ixodes and Ambliyomma [10,11,[27][28][29]. In our study, the only tick species found in all the samples taken was Rhipicephalus turanicus.…”

Evaluation of an Indirect Immunofluorescence Assay for the Detection of Anaplasma phagocytophilum Antigen in Ovine Buffy Coat Smears

“…In humans, A. phagocytophilum causes human granulocytic anaplasmosis (HGA) and it is the causative agent of tick-borne fever (TBF) in sheep and goats and pasture fever in cattle [6]. TBF is a challenging and wasting condition with severe economic impact and welfare challenges in the small ruminant industry [9]. High fever (>41 • C) is the most characteristic symptom of the disease in domestic ruminants, while weakness and anorexia are also commonly reported.…”

“…or Mannheimia septicaemia, is reported due to immunosuppression. Abortion, stillbirth, reduced milk yield, impaired spermatogenesis in males, low fertility in sheep and reduced weight gain in young animals are among the most commonly occurring complications [2,6,9,10].…”

Haemoparasites and Polyparasitism of Intestinal Helminths of Cattle Slaughtered in Abeokuta, Nigeria and Their Implications for One Health.

“…Haemoprotozoan diseases especially Babesiosis, Anaplasmosis, Trypanosomiasis and Theileriosis are major diseases causing major constraints to the health and productivity of cattle (Ochai & Kolhatkar, 2007). Even though there is a global distribution of haemoparasites, the distribution of these infections changes continuously due to the migration and transportation of vectors and animals and an increased globalization of both live animals and their products (Stuen, 2020).…”