Chullin 59 - Which Animals Are Kosher?
If an animal inhaled smoke, was overcome by cold, or ate animal poison - all of which are dangerous to animals but not to humans - it is kosher. If it ate human poison or if it was bit by a snake, it is still kosher, but it is prohibited to eat it because of a potential danger to human life.
Once a deer had its hind legs severed. Rav inspected it and, because the cut was below the sinews of the knee, pronounced it kosher. He wanted to taste it lightly roasted, but Shmuel said to him, "Perhaps a snake bit it before the leg was severed. Put it in the oven to check." The meat was indeed poisoned and fell apart. Shmuel applied to Rav the words of Solomon, "No harm shall befall a righteous," and Rav applied to Shmuel the words of Daniel, "No secret is withheld from you."
The signs of a kosher domestic and of a kosher wild animal are listed in the Torah: it should have hooves that are completely split into two, and it should be a ruminant that brings up its cud.
Art: Winslow Homer - Fallen Deer