Ive always heard to eat rabbits only in the months that do have R in them, because usually that is the colder months. Its because the rabbits carry diseases and the cold weather kills them. I don't know if its true or not but I certainly wouldn't want to risk getting a disease.
It's true. They develop a parasitic worm which can be found under their skin in their armpit. They are active, roughly speaking, during the months that have an "r" in them. You mostly have this problem when hunting wild rabbit. To those who don't believe it, I would advise double checking your rabbits. You wouldn't want to accidently eat one of those worms. They're horrid.