Eimeria brunetti and Eimeria necatrix in chickens of Argentina and confirmation of seven species of Eimeria

Ten poultry farms (broiler breeder pullets, layer pullets, and broilers) in the provinces of Entre Rios and Buenos Aires in Argentina were examined for presence of Eimeria spp. Litter samples obtained from flocks 7-11 wk old were taken to the laboratory for oocyst counting and sporulation, then concentrated for inoculation into coccidia-free chickens. Species were identified by prepatent period, oocyst size, location and appearance of lesions in the intestine, microscopic examination of mucosal smears, and histology (to confirm Eimeria brunetti). On this basis, Eimeria praecox was found in two samples, Eimeria mitis in two, Eimeria acervulina in nine, Eimeria maxima in seven, Eimeria necatrix in three, Eimeria tenella in seven, and E. brunetti in four. These results confirm the presence of all seven recognized species of Eimeria in chickens in the Republic of Argentina.