Chullin 33 - Blood of Shechitah and Ritual Impurity
To become susceptible to ritual impurity, food must first become wet, as the Torah said, " any usual food that has [once] been wet with water shall become unclean ". In addition, the owner of the food must be content with it becoming wet. Thus, washing the fruit would qualify, while the fruit falling into the water would not.
The slaughter of an animal produces blood, and the owner of the animal is content with it, thus blood prepared the animal to become ritually impure. However, we have a rule that states "if one slaughtered a domesticated animal, a wild kosher animal, or a bird, and blood did not come out of them, they are kosher. We do not assume that the animal died just prior to shechitah. It may be eaten with unwashed hands."
Unwashed hands are considered ritually impure. But why should this rule be true? It cannot be talking about sacrifices, because kosher wild animals, such as deer, are never brought as sacrifices. The only situation where this rule can be applicable is when animals were bought with the money of the second tithe.
Art: Jean-Baptiste Oudry - A Deer Chased by Dogs