Experimental Eperythrozoon ovis infection of sheep

Abstract

Extract

Eperythrozoon ovis is an epi-erythrocytic sheep parasite of uncertain classification with a world-wide distribution (Sutton, 1970), but whether eperythrozoonosis is a disease of economic importance remains unresolved. In Scotland, Foggie and Nisbet (1964), found that experimentally E. ovis caused a clinical anaemia, occasionally with jaundice, but there was no significant difference in weight gain between infected and control sheep. Similar observations in naturally infected sheep were recorded in Norway by Overas (1969), and in Australia by Harbutt (1969b), Other Australian authors have found infection by this parasite; associated with outbreaks of ill-thrift in lambs (Sheriff et al., 1966) and severe anaemia with some mortality (Littlejohns, 1960; Maxwell, 1969; Campbell et al., 1971). Although the presence of strains of different pathogenicity has been suggested (Foggie and Nisbet, 1964, 1966; Harbutt, 1969a), other factors influencing the disease should also be considered (Littlejohns, 1960).