He could do this on and off until the disease have affected so bad that he would be down permanently, then you have to have food right there by his beak in order for him to eat as well as water. Sometimes they can die by drowning in there water. But it does sound like he is progress is getting worst.I have one last question before I cull...
When they go down on the splits, are they able to get back up again and walk before going down again.
Juicy started doing the splits again today, chirping wildly, before pulling his legs back together and stilt walking around. The left one still seems to go forward.