Perhaps we're musical and independent like the New Guinea vocal singing dog. A mule is not a pet varieties, like a horse or donkey. Cysts are shed or passed from the contaminated animal with its feces. Some trophozoites do not enter into the cyst kind but obtain passed right into the feces. However, trophozoites can not survive for long in the environment as well as are unable to cause infection if consumed by an additional pet. Upon reaching the small intestines, the trophozoites exit the cysts, mature, divide, as well as ultimately go back right into cyst form.