OK, we have 3 brown leghorn chicks, about 3 weeks old. They were all happy and healthy until we noticed today that one was kind of flopping to the food and water. It looks like its legs don't work. The left one will curl around my hand but the right one just hangs there. I can't feel any breaks or problems...it just feels like dead weight. I'm gonna have to cull this poor thing, aren't I?