2,534. Indications That an Animal Was Attacked

Hilchos Shechita 5:9

“An indication that the animal was attacked” (in the previous halacha) means that the flesh opposite the intestines has reddened. If the flesh opposite the intestines putrefies to the point where it’s like flesh that a doctor would remove from a wound, we consider that flesh to be deficient and the animal a treifa.

Hilchos Shechita 5:10

If a predator attacked an animal’s signs (i.e., the trachea and the esophagus), the animal’s a treifa if they redden; this applies to even the smallest wound. If the tiniest part of them reddens from an attack, it’s a treifa.