2,569. An Animal's Kidneys

Hilchos Shechita 8:25

If an animal’s uterus or kidneys were removed, it remains permitted. Therefore, if the animal was born with just one kidney, or with three kidneys, it is permitted. The same is true if a kidney is punctured.

Hilchos Shechita 8:26

While an animal remains permitted if a kidney was removed or if it was born without it, if a kidney is particularly small, the animal’s a treifa. The intended size for the purposes of this halacha is the size of a bean in a small animal and the size of a grape in a large animal. The same is true if a kidney is stricken so that it’s like dead flesh that has decayed for several days with the result that handling it would cause it to crumble and fall apart. If this affliction reaches the white part of the kidney, the animal’s a treifa. If moisture is found in the kidney, even if it’s not fetid, or if murky or fetid liquid is found there, it’s a treifa. If clear liquid is found there, the animal remains permitted.