2,585. Two More Reasons (for Birds)

Hilchos Shechita 10:10

The 70 conditions that cause a domesticated or wild animal to become a treifa were each communicated with their specific laws. All the organs in a bird that are analogous to the organs of an animal follow the same rules with the exception of the things in kidneys, spleen and lobes of the lungs that make an animal a treifa. This is because a bird doesn’t have divided lobes like an animal does; if it does have such a division, there’s no requisite number. A bird’s spleen is round like a grape and not shaped like that of an animal. The things in the kidneys and spleen that make an animal a treifa weren’t mentioned regarding the analogous organs of a bird. Accordingly, no particular size was given for a bird whose kidney shrank. The same is true in other comparable cases.

Hilchos Shechita 10:11

Two things make a bird treif on top of those that make an animal treif, even though animals also have these organs: a fowl whose intestines changed color from fire and a water fowl whose skull was punctured.