Coccidia: A subclass of protozoans commonly parasitic in the epithelial cells of the intestinal tract but also found in the liver and other organs. Its organisms are found in both vertebrates and higher invertebrates and comprise two orders: EIMERIIDA and EUCOCCIDIIDA.Eimeria: A genus of protozoan parasites of the subclass COCCIDIA. Various species are parasitic in the epithelial cells of the liver and intestines of man and other animals.Coccidiosis: Protozoan infection found in animals and man. It is caused by several different genera of COCCIDIA.Eimeriidae: A large family of parasites in the order EIMERIIDA. They cause COCCIDIOSIS in a number of vertebrates including humans.Isospora: A genus of protozoan parasites found in the intestines of birds, amphibians, reptiles, and mammals, including man. The oocysts produce two sporocysts, each with four sporozoites. Many species are parasitic in wild and domestic animals.Robenidine: An anticoccidial agent mainly for poultry.Coccidiostats: Agents useful in the treatment or prevention of COCCIDIOSIS in man or animals.Oocysts: Zygote-containing cysts of sporozoan protozoa. Further development in an oocyst produces small individual infective organisms called SPOROZOITES. Then, depending on the genus, the entire oocyst is called a sporocyst or the oocyst contains multiple sporocysts encapsulating the sporozoites.Sarcocystis: A genus of protozoa found in reptiles, birds, and mammals, including humans. This heteroxenous parasite produces muscle cysts in intermediate hosts such as domestic herbivores (cattle, sheep, pigs) and rodents. Final hosts are predators such as dogs, cats, and man.Eimeria tenella: A species of coccidian protozoa that mainly infects domestic poultry.Poultry Diseases: Diseases of birds which are raised as a source of meat or eggs for human consumption and are usually found in barnyards, hatcheries, etc. The concept is differentiated from BIRD DISEASES which is for diseases of birds not considered poultry and usually found in zoos, parks, and the wild.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Toxoplasma: A genus of protozoa parasitic to birds and mammals. T. gondii is one of the most common infectious pathogenic animal parasites of man.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.