1. No liver is a defect. But can an animal live without a liver?
2. Clawed by a wolf. Wolves don't inject poison. The notes say the poison could be bacteria from declayed meat in its claws. Let's say the wound occurred on the arm (no broken bones). Then the poison kills it just like snake venom, which doesn't cause a tereifah! Why then does it cause a tereifah?
Barry Epstein, Dallas, USA
1. It is a defect precisely because the animal cannot live without it. Nonetheless, the act of removal of the liver does not kill the animal immediately. There is time to slaughter it with Shechitah before it dies from lack of a liver. Moreover, the Chidush of the Mishnah seems to be that only removal of the entire liver causes the animal to be a Tereifah, but the animal indeed can live with part of its liver intact.
2. First, the Gemara (53b) says that the wound must be near a vital organ to cause the animal to be a Tereifah. Second, not all wounds cause an animal to be a Tereifah. If an animal's major vein in its leg is cut by a knife and the animal is bleeding to death, the animal is not a Tereifah; it is a "Mesukenes." If it is slaughtered before it dies, it is a Kosher Shechitah. Physical damage to a specific organ is necessary to render the animal a Tereifah (fatally defected); a systemic injury merely renders the animal a Mesukenes or Goses (a dying animal). (See Sefer ha'Eshkol, Tereifos 15).
Y. Shaw