So here's something maybe one of you can help me with. I've lost a handful of birds that all of a sudden become weak, then lose control of their "muscles" becoming lame and sometimes contorted, like something out of one of those "exorcism" movies. Iris does not change color, They don't appear ill, other than the weakness, paralysis, and some remain fairly functional. No visible or palpable lesions. Difference in stool production and consistency seems to be related to an inability to feed/drink adequately. Almost without fail, it happens in one line of my OEGB, although other varieties have been affected, It is extremely random as to when they are afflicted, but almost always occurs in birds less than 3 months of age. It does not appear to be contagious, as birds in the same cages rarely are affected, and when they are, months elapse in between occurrences. The first time it happened, I isolated and the pullet dramatically improved after a short time, only to relapse later. She just couldn't get enough to eat or drink and had to be culled. I hate it, but I cull anything quickly now that has the appearance of being ill. I have too many to risk just to try and save one sick bird. Some version of "Mareks"? Something else? Any ideas?