- Dog is the definitive host of Sarcocystis cruzi. The ruminant is an intermediate host. Sarcocystis hirsuta involves the cat as the definitive host. Primates are the definitive host for Sarcocystis hominis. The life cycle involves a carnivore eating an infected cow which has cysts in the muscle. Then the cyst eventually forms sporocysts which are shed in feces and subsequently eaten by more cows. The sporocysts then hatch and penetrate artery walls and hang out in the endothelium to develop into sporozoites and eventually become merozoites at which time they invade muscle and encyst as sarcocysts. It takes about 10 weeks for the entire maturation process to occur. Clinical signs are non-specific such as fever, anorexia, salivation, weakness, muscle fasciculations, and weight loss. Diagnosis is likely to be at necropsy; so, prevent carnivore feces from contaminating the area.
- The definitive host of Sarcocystis hirsuta is the cat and for Sarcocystis hominis, it is the human.