2,517. Invalid vs. Doubtful

Hilchos Shechita 3:18

Whenever we say that shechita is invalid, it means that the animal is a neveila and that one who eats an olive-sized portion of it is liable to the penalty of lashes for eating it. Only valid slaughter as taught to us by Moshe keeps an animal from being a neveila as has been discussed. If there’s a doubt involving shechita, then there’s a doubt as to whether the animal is a neveila. One who eats from it incurs stripes for acting rebelliously.

Hilchos Shechita 3:19

If an animal’s thigh and its hollow were removed so it appears to be incomplete when crouching, the animal is a neveila as if half of it was removed so that it was split into two bodies. Accordingly, shechita is ineffective on such an animal. Similarly, if the spine is broken along with most of the meat, if the back is torn open like a fish, if the greater part of the trachea was severed, or if the esophagus was punctured in a place where slaughter could be performed – in all of these cases the animal is like a neveila while it’s still alive so shechita is ineffective on it. The same rules apply both to animals and to poultry in all these matters.