We have 4 emus, 2 we have hatched out and raised as babies. One of those 'youth' emus seems to be very weak, very thin and we have to help him/her up from time to time. The others are all fine, any ideas of what might be wrong? it is the smaller of the two youth birds, but only by a little bit, and there has never been any indication prior to it being treated as runt, etc. We live in Northern California, mild temperatures, and the birds are pastured, and fed grain and various fruits. Any advice is appreciated, thanks !