title: Polymorphism of eimerian oocysts: a dilemma posed by working with some naturally infected hosts.
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000469:parasitology*; D001717:Birds; D003048:Coccidiosis / Q000469:parasitology / Q000662:veterinary*; D004539:Eimeria / Q000145:classification / Q000648:ultrastructure*; D007411:Intestinal Diseases, Parasitic / Q000469:parasitology / Q000662:veterinary*