Effect of Eimeria maxima infection on development of Eimeria tenella in immunized chickens.

Chickens previously immunized against Eimeria tenella were reinfected with this species with and without infection by E. maxima. The present of E. maxima at the time of reinfection appears to decrease the immunity of the animals and enables E. tenella to develop. In this case, the development of E. maxima is not affected by the presence of E. tenella.