In attempting to find what the heck is wrong with my hen, I found this chart that is easy to read and clear to understand for a lot of the ailments we seek info. on. Just thought it might be helpful to others.
http://web.uconn.edu/poultry/poultrypages/diseasefactsheet.html
http://web.uconn.edu/poultry/poultrypages/diseasefactsheet.html