Yosef Karo, Shulchan Aruch — 58 Laws of a beast that fell
“ A beast that fell, if it was standing on its legs when it fell, if there's from its belly to the place it fell 10 Tefach we are concerned it has crushed parts. And if it was was lying and rolled down to fall, the height of the place needs to be ten Tefach. ”
