An animal is only kosher for consumption if it is in good physical health at the time of slaughter. The Mishnah lists various terefos, fatal defects, which render an animal prohibited for use as food. One of these fatal defects is a mauling by a wolf:
These are the terefos in domesticated animals… if it fell from a roof, if most of its ribs were broken, a mauling by a wolf; Rabbi Yehudah says, a mauling (derusah) by a wolf [is considered a fatal defect] with a small domestic animal, and a mauling by a lion [is considered a fatal defect] with a large animal. (Mishnah, Chullin 3:1)If a wolf mounts an unsuccessful attack against a large animal such as a cow, the animal is not considered to be mortally wounded and it may still be slaughtered for human consumption. Only with small livestock, such as sheep and goats, is a mauling by a wolf considered a fatal defect.
A difficulty with this topic is that the Talmud states that the result of such derusah is that venom is injected into the prey animal (Chullin 53a). Needless to say, this is not consistent with modern zoological knowledge of wolves.
One solution presented for such difficulties (Rabbi Eliyahu Dessler, Michtav Me-Eliyahu, vol. IV, p. 355, footnote 4) is that the Talmud is not referring to a chemical venom generated by the animal, but rather to infections caused by bacteria accumulating in the animal. A variation on this would be to say that bacterial infections led to the belief that venom is injected.
At the moment, I am more concerned with a second difficulty. The Talmud (Chullin 53a) rules that these maulings which are rated as causing fatal defects are referring to maulings inflicted with the claws, not with the teeth (which is implicit in the term derusah, which usually means "trample"). But this conflicts with contemporary observations of wolves, which reveal that wolves never attack prey with their claws, only with their teeth.
The reason why wolves never attack with their claws reflects the very different hunting strategy of wolves compared to members of the cat family such as lions and leopards. A big cat is an ambush predator. It is not built for running at speed, but rather for firmly seizing its prey. It uses its strong arms and claws to grasp its prey, enabling it to make a killing bite in a precise spot. Wolves, on the other hand, are pursuit predators. The legs of a wolf are slender, and the paws are not jointed for grasping; its body is built for long-distance pursuit, not for bringing down prey. The wolf’s claws are strong, but very blunt, because the tips are worn off by constant contact with the ground. These are used for digging and gripping the earth while running, not for seizing or killing prey. Wolves kill with a large number of minor slashing bites.
What, then, are we to make of the Talmud's statement that derusah is only with the claws? Must it be considered an error?
I would like to suggest a way to slightly lessen this problem, if not to solve it entirely. In an entirely unrelated Gemara, we have the following case:
A shepherd was tending a flock, but left them and went to the town, and a wolf came and was taraf, and a lion came and was dores… (Talmud, Bava Metzia 93b)Here we seem to have a contrast presented between the typical modes of attack of a wolf and a lion. A lion is dores. A wolf, on the other hand, is toref. But what is the difference between these two modes of attack? Rashi explains that dores refers to instantaneous slaughter, whereas toref refers to wounding the sheep and then dragging it back to a lair for later consumption. But Rabbeinu Chananel to Bava Kama 16b refers to this Gemara and seems to explain it differently: that dores refers to killing with claws, whereas toref refers to killing with its teeth. He further states that this Gemara expresses the typical difference between attacks by lions and attacks by wolves. This is consistent with our knowledge of how wolves kill.
But then, what of the Gemara in Chullin which only lists derusah as causing predator-inflicted terefos, including by wolves, and later says that derusah is only with claws? Is it simply disputing the Gemara in Bava Metzia? Or is there some way to explain the latter statement of the Gemara as only referring to the derusah of certain predators? Or is the Gemara in Chullin not disputing the fact that wolves usually attack with their teeth, and is simply saying that only in the rare case of an attack with their claws would it be considered a terefah? What would Rabbeinu Chananel have said about it?
Your input is appreciated!