I was on Prednisone for a short time while I was in the hospital being treated for ulcerative colitis the summer of 09'. I also was still on it when I came home... a month later! Ugh! Anyway, pred is not to be used long-term, as you said, overtime it does affect your liver. It aslo weakens your immune system, so stay away from crowded places (malls, resturants, etc) until you get the okay from your Dr. You cannot just suddenly stop taking prednisone, or other steroids for that matter, you have to be weaned off of the drug, following the instructions from your doctor.

For animals, (don't know much about people and prednisone, other than my own personal experience) they eat and drink a whole lot more!