• אלו טרפות בבהמה

The third Perek begins: אלו טרפות בבהמה – these are tereifah in animals. The Mishnah enumerates eighteen different defects which prohibit an animal in consumption: (1) נקובת הוושט – [an animal] whose esophagus is punctured, (2) פסוקת הגרגרת – one whose trachea is severed, (3) ניקב קרום של מוח – if the membrane of the brain was punctured, (4) if the heart was punctured into its chamber, (5) if the spine was broken and its cord severed, (6) if the liver was removed and nothing remains of it, (7) הריאה שניקבה – if the lung was punctured, (8) או שחסרה – or was deficient, (9) if the קבה – abomasum (fourth stomach) is punctured, (10) if the מרה – gallbladder was punctured, (11) if the דקין – intestines were punctured, (12) if the כרס הפנימית – inner paunch (first stomach) was punctured, (13) if most of the outer כרס was torn, (14) if the מסס – omasum (third stomach) or (15) the בית הכוסות – reticulum (second stomach) was punctured to the outside, (16) if it fell from a roof, (17) if most of its ribs were broken, or (18) if it was clawed by a wolf.

• Machlokes if a טריפה can live

The Mishnah concludes: זה הכלל – this is the rule: כל שאין כמוה חיה טרפה – any [animal] the likes of which cannot live because of its defect is a tereifah. This implies that no tereifah can live (for more than a year), and this is alluded to in the passuk: וזאת החיה אשר תאכלו – and this is the animal that you may eat, teaching: חיה אכול – [an animal] which can live, you may eat; שאינה חיה לא תיכול – [an animal] which cannot live (i.e., a טריפה), you may not eat. According to the opinion that a טריפה can live (for more than a year), this is derived from a Baraisa taught in Rebbe Yishmael’s yeshivah: בין החיה הנאכלת ובין החיה אשר לא תאכל – between the animal which may be eaten and the animal which may not be eaten (the word "חיה" implying that although it can live, it still may not be eaten), אלו שמונה עשרה טרפות שנאמרו למשה מסיני – these are the eighteen types of tereifos which were told to Moshe at סיני.

• More types of tereifos: בסג"ר and שב שמעתתא

The Gemara objects that there are more טריפות than the eighteen listed in our Mishnah, four referred to with the acronym בסג"ר, and seven more known as "שב שמעתתא" – the seven teachings!? Although our Mishnah does not mention a specific number of טריפות, and these additional types can be included in the "כלל" in the Mishnah’s conclusion, but Rebbe Yishmael’s Baraisa says there are only eighteen!? "בסג"ר" refers to: (1) בהמה שנחתכו רגליה מן הארכובה ולמעלה – an animal whose hindlegs were severed above the joint, (2) חסרון בשדרה – a deficiency in the spine, (3) גלודה – a flayed [animal], and (4) חרותא – [an animal] with a shriveled [lung]. The list of "שב שמעתתא" is: (1) a thighbone which popped out of its socket, (2) a diseased kidney, (3) a punctured spleen, (4) most of the סימנים were detached, (5) a rib was uprooted from its base, (6) the skull was mostly crushed, and (7) the flesh that covers most of the כרס is damaged. The Gemara proceeds to explain how all these additional cases are accounted for in the eighteen טריפות.