My cat is very old, about twenty, and she hasn't had a single health problem her whole life, except the occasional cold. i was petting her belly the other day and noticed that one of her nipples didn't look right. The "tube" leading up to it is swollen and purple. I'm not even sure it's the tube, or if it even works like that...but on a day to day basis, it doesn't seem to bother her. It's like she doesn't notice, but the nipple itself is basically on it's side, instead...