Use of microscopic lesion scores, gross lesion scores and oocyst count scores to detect Eimeria maxima in chickens.

We recently found that the microscopic lesion scoring (MLS) method is superior to gross lesion scores (GLS) for detecting endogenous stages of Eimeria maxima in chickens. In the present study, the MLS was found to be superior to either oocyst count scoring (OCS) or GLS for detecting E. maxima infections in broiler chickens, and the OCS was better than the GLS. For chickens in all companies and at all geographic locations, the MLS located more E. maxima than did the OCS or the GLS. Though used widely and routinely, the GLS does not detect E. maxima that can easily be located with other methods. Therefore, the GLS may not be suitable for use in health programmes that depend upon detection of E. maxima in broiler chickens.