In 1995, Out of 450 white turkey poults suffering from emaciation diarrhea and interitis in Giza province, only 46.7% cases were recorded positive to cryptosporidiosis through out the year, 22% in winter and 24.7 was fluctuated through out the other seasons. Cryptosporidia was isolated from
ileum, colon, ceaca, and bursa of fabricius while it was not observed in the duodenum or trachea. The prepatent and patent as well as the different developmental stages of Crytosporidium parasite in experimentally inoculated turkeys were mentioned. Histopathological studies of affected tissue were done indicating the attachment of organism to epithelial lining of the intestine resulting in vascular degeneration, Edema, proliferation of eosinophils and lymphcytes. The bursa of fabricius, showed depletation of the lymphoid follicles accompanied with attachment of the plical epithelium including the parasitic structure. Using of ammonia 5%, gave the most destructive effect on Crytosporidium oocysts at least time (30 minuts) than formaldehyde or iodophore disinfectants.