A possible relationship between coccidial and clostridial infections in commercial broilers has long been controversial, not least because of the problems of interpretation caused by the use of in-feed ionophorous drugs, which may be active against both pathogens. The results of definitive, controlled laboratory experiments are now beginning to provide a better understanding of interactions between coccidia and clostridia, and the effects of using anticoccidial vaccines.
This article can also be found in World Poultry, Coccidiosis 4