The pathogenic effects of <i>Eimeria praecox</i> and <i>E. acervulina</i> in the chicken

Abstract

Eimeria praecox produced less effect on body-weight gain and food consumption than E. acervulina . No deaths occurred and no weight loss followed infection with doses of oocysts up to 10. However, there was a depression of body-weight gain in birds infected with both species and changes in the permeability of the intestine were noted from as early as 3½ h after infection. This suggests that increased intestinal permeability is not the major factor in the greater pathogenicity of E. acervulina compared with E. praecox. Eimeria acervulina produced considerably greater effects on the host as evidenced by mortality, body weight gain and food consumption. I wish to thank Mr B. J. Millard and Mr M. Shirley for technical assistance and Dr B. M. Freeman for help with the statistics in Table 2.