Those drugs are for treating respiratory or other issues. Corid is the best treatment for coccidiosis. Dimethox and Sulmet are also used, but are not as good (don't treat all of the strains,) or have harsh side effects(sulmet). Dimethox however will treat cocci plus other bacteial diseases...
Coccidiosis probably. Did you treat with Corid yet? It is a safe drug for egg layers and meat birds alike. Liquid 2 tsp or powder 1 tsp per gallon of water for 5-7 days.