I have a 15 year old white ringneck dove that has started preening excessively, seems as though he feels very itchy. It’s annoying him a great deal. I have three other doves that are not having this problem, so I really doubt that parasites are a possibility. In addition, they all live indoors with me. I did examine him to see if I could find anything, but there was nothing I could find. I do have central heating on and live in a very dry climate – could this be the problem? Any suggestions would be most appreciated. I did just turn on my humidifier to see if this would help.