Pesachim 98 - Shabbat, Shushan Purim, February 27, 15 Adar

What are the laws for one who designates an animal for a Pesach sacrifice that cannot be used as it is too old or female? What if one dies before the sacrifice is brought? What can the inheritors do with the animal? On what does it depend? What if a Pesach gets mixed up with other sacrifices and one does not know which is which? What if one group's animal got mixed up with another's?