2,572. The Meaning of "Torn"
Hilchos Shechita 9:5
“Torn” refers to the flesh that covers the greater part of an animal’s abdomen; if it's torn open, the abdomen will fall out. If this flesh is torn open, the animal’s a treifa; this is so even if the tear doesn’t reach the abdomen enough for it to be seen. However, since the greater part of this flesh’s width was torn or removed, the animal’s a treifa. Such a tear must be a handbreadth long (about three inches). If an animal is small and the greater part of the length of the flesh on the abdomen is torn, it’s a treifa even if the tear’s not a handbreadth long, because the greater part was torn.
Hilchos Shechita 9:6
If a round or oval piece of this flesh was cut and it’s larger than a sela (a denomination of coin), which is big enough for three date seeds to fit tightly into next to one another, the animal’s a treifa. This is because if a tear of this size were extended, it would be a handbreadth long.