Dear Rabbi,

Why don't you have to check a chicken's lungs as you would a cow's to ensure that it's kosher?

Dear Daniele Kurzweil,

We check only for frequently existing problems. A lesion on the lungs of a cow is quite common, while in a chicken it is uncommon.

It's interesting to note that there is a Rabbi in Jerusalem who maintains that the percentage of problems in chicken lungs has grown lately, and he therefore supervises a special line of kosher chickens in which the lungs are checked.