Zevachim 7:6: If one pierced [a bird's neck] and it was found to be a Terefah [an animal with a mortal condition such that it would die within one year], Rabbi Meir says: It does not render a person impure through swallowing. Rabbi Yehudah says: It does render a person impure through swallowing. Said Rabbi Meir: If the slaughtering of an animal [which if it were a] Nevelah [an improperly slaughtered animal of a permitted species] would transmit impurity via touch and carrying, [nevertheless] loses its ability to transmit impurity [if it were a] Terefah, then a bird [which if it were a] Nevelah would not transmit impurity through touch or carrying, should certainly [cause] a Terefah, if slaughtered, to lose its ability to transmit impurity. Just like we find that slaughtering [a bird] permits it to be eaten, and removes the ability of a Terefah to transmit impurity, so too piercing [a bird's neck] permits it to be eaten [should] remove the ability of a Terefah to transmit impurity. Rabbi Yose says: It is sufficient [to compare a Terefah bird] to a neveilah animal [such that] slaughtering removes its ability to transmit impurity, but piercing [its neck] does not.

מלק ונמצא טרפה - רבי מאיר אומר: אינה מטמאה בבית הבליעה. רבי יהודה אומר: מטמאה בבית הבליעה. אמר רבי מאיר: מה אם נבלת בהמה, שהיא מטמאה במגע ובמשא, שחיטתה מטהרת את טרפתה מטמאתה, נבלת העוף שאינה מטמאה במגע ובמשא, אינו דין שתהא שחיטתה מטהרת את טרפתה מטמאתה? מה מצינו בשחיטתה שהיא מכשרתה באכילה, ומטהרת את טרפתה מטמאתה, אף מליקתה שהיא מכשרתה באכילה, תטהר את טרפתה מטמאתה. רבי יוסי אומר: דיה כנבלת בהמה - שחיטתה מטהרתה, אבל לא מליקתה.

Zevachim 8:1: Any offerings which became mixed up with chata'ot [offerings brought to expiate sin][designated to] die, or with an ox [designated to be] stoned, even if it be one among ten thousand - they all must die. If they became mixed up with an ox that was used to commit a sin, or [with an ox] which killed a person based on [the testimony of] a single witness, or based on [the testimony of] the owners, or with an ox that had relations with a woman, or with whom a man had relations, or with an ox designated for idolatry, or which was worshiped, or with an ox that was used to pay a prostitute, or which was exchanged for a dog, or with a mixed breed, or with a Terefah [an animal with a mortal condition such that it would die within one year], or with an animal born through Caesarean section - these are [all] set to graze until they become blemished, and then they are sold. And one brings [a new animal] equal in value to the most valuable among them, for the same type of sacrifice. If [a sacrifice] became mixed up with unblemished non-consecrated animals, the non-consecrated animals are sold to those requiring that type of sacrifice.

כל הזבחים שנתערבו בחטאות המתות, או בשור הנסקל, אפלו אחד ברבוא - ימותו כלם. נתערבו בשור שנעבדה בו עברה, או שהמית את האדם על פי עד אחד, או על פי הבעלים: ברובע, ובנרבע, ובמקצה, ובנעבד, ובאתנן, ובמחיר, ובכלאים, ובטרפה, וביוצא דפן - ירעו עד שיסתאבו, וימכרו, ויביא בדמי היפה שבהן מאותו המין. נתערב בחלין תמימים - ימכרו החלין לצריכי אותו המין.