Chullin 54

Sugya Map: The Mechanics of Drusah

• Core Issue: Does the drusah (clawing) of a predator render an animal tereifa because of the physical perforation or the biological action of the venom?
• Nafka Mina: Whether the shiur (measure) of the injury is fixed by the size of the wound or defined by the potential for the venom to spread.
• Primary Sources: Chullin 54a; Mishnah Chullin 42a; Rif Chullin 16a.

Text Snapshot

The Gemara asks regarding the windpipe (kaneh): "If clawed, what amount of its flesh must redden... [the Gemara] resolved it: Both this and that render the animal a tereifa if any amount of its flesh reddened. What is the reason for this? It is because its venom burns continuously (zihra mikla kali ve-azil) around the circumference of the hole and widens it" Chullin 54a.

Dikduk Note: Rashi (s.v. zihra) emphasizes the process of akila (eating away), framing the tereifa status not merely as a result of a static wound, but as a dynamic, progressive pathology.

Readings

• Rashi: Argues that the tereifa status is rooted in the "future" state (sofo lin'kov); the venom is a catalyst that inevitably leads to a fatal perforation.
• Dor Revi'i: Challenges this by contrasting it with Tosafot. He argues that if the venom’s burning is the tereifa itself—an independent category of injury—then the "any amount" rule is a halacha le-Moshe mi-Sinai regarding the nature of predatory toxins, rather than a mere prediction of future decay.

Friction: The Drusah Dilemma

Kushya: If the kaneh (windpipe) requires a hole the size of an issar to be tereifa via static perforation, why does a "clawed" windpipe render it tereifa at any amount of redness? Terutz: The Gemara distinguishes between a mechanical wound (which has a size threshold) and a biological infection (the venom), which acts as a corrosive agent. As the Dor Revi'i suggests, the "reddening" is not the injury itself, but the signature of the venom that will inevitably destroy the organ, rendering the shiur irrelevant.

Psak/Practice

The halacha follows the stringent view that drusah requires inspection. Even if the wound appears minor, if the flesh is reddened, the animal is disqualified. The "reddening" is the clinical diagnostic for the presence of the predator’s venom. Modern shechita practice relies on this; if the simanim show signs of drusah, one does not measure the hole—the presence of the chemical reaction is the tereifa.

Takeaway

The difference between a nevila and a tereifa often hinges on whether the fatal process has already begun. In drusah, the issar measure is a limit for mechanical trauma, but the venom’s "burning" creates a qualitative, rather than quantitative, state of death.