Eimeria adenoeides and E. meleagrimitis: Pathogenic effect in turkey poults

Abstract

The pathogenic effects of infection with freshly sporulated oocysts of E. adenoeides and E. meleagrimitis were studied in 3-week-old turkey poults. The high pathogenicity of E. adenoeides and E. meleagrimitis was confirmed. Small doses of oocysts led to depressed weight gains and a high production of oocysts. The severity of infection increased progressively as the dose increased. Mortality tended to coincide with schizogony at high levels of infection and with gametogony at low levels of infection. The acute phase of the disease lasted from the third or fourth day to the sixth or seventh day after infection. The pathogenic effect of E. adenoeides appeared greater than that of E. meleagrimitis in birds fed an equivalent number of oocysts. Infection with E. adenoeides is recognised by haemorrhagic enteritis in the distal part of the small intestine, the large intestine and the proximal part of the caeca; lesions caused by E. meleagrimitis are confined to the proximal part of the small intestine.