Went to give my rats a treat this afternoon and noticed one of my boys is pretty lathargic, won't eat anything. One of his eyes is swollen shut. I'm thinkin it could be a part that my cats pushed my back door open where my rats are and it got pretty cold that night. Any ideas on what I can do to help this little guy? He's just turning two. His brother would be devistated without him. Any notice would be greatly appreciated.