Chullin 56 - These are the Cases of Terefah in Fowl
These are the cases of terefah in fowl: a bird whose esophagus was punctured, or one whose trachea was severed. If a weasel struck (bit) it on its head in a place that makes it a terefah, that is, opposite the brain, and there is a concern that the brain membrane may have been punctured. If the gizzard was punctured, or if the intestines were punctured.
If a fowl fell into fire and its internal organs were scorched, then if they turned green, it is terefah, but if they remained red, it is kosher. If one trod on a fowl or knocked it against the wall, or if an animal crushed it, then if it fluttered and remained alive for twenty-four hours, and one then slaughtered it, it is kosher.
Art: Wallerant Vaillant - Young Sportsman with Rabbit and Fowl