Phylum: Apicomplexa

Suborder : Eimeriina

Family : sarcocystidae

Sub-family: sarcocystinae

Genus Sarcocystis

Family: Sarcocystidae

• His family includes six-genera: Besnoitia, Hammondia, Sarcocystis, Neospora, Erenkelia and Toxoplasma which are of veterinary interest.
• Asexual stage of life cycle occurs in intermediate host and sexual stage occurs in final host.
• Oocyst have two sporocysts each with four sporozoites.
• Except, Toxoplasma, they are normally non-pathogenic to their final host and significance is due to cystic tissue stage in intermediate host; which include ruminants, pigs, horses and humans.
• Tissue phase in intermediate host is obligatory except toxoplasma, where it is facultative.