Thank you to everyone for their advise and the name of the paste! I appreciate all of you taking time to write!
This little keet has been a mystery! Saturday night after working with it for hours it finally got up. It was running around, looked better and stronger. Started eating the feed and drinking water from it's waterer. You couldn't tell anything had ever been wrong with it. I put it back with the others, checked on it again before going to bed, everything still fine.
Got up Sunday morning and there it was laying on it's side again looking lifeless, same as the morning before. So everything was repeated as had been done the day before. By mid-afternoon it was active, looking great, even walking straighter than it had been on Saturday but decided not to put it back in with the others yet. Instead I pieced together a small cage and placed it there for the rest of the day to watch. When it came time to go to bed I put it back with the others but sat there and watched. I had reached the conclusion it couldn't be sick with any kind of disease since it was perking up too quickly after working with it and removing it from the cage with the others so something else was going on.
Sure enough, after a couple of minutes the others started pecking it, knocking it down, stepping all over it and pushing it aside. They kept this up until it was getting too weak to get back up so I removed it and placed it in the separate cage permanently. It's the smallest of the 6 keets, almost half the size of the biggest one, so it makes sense it would get knocked around some but the other keets were purposely abusing this one. It did great yesterday in the separate cage so I was hopeful we were on the road to recovery but this morning when checking it was on it's side AGAIN. It can stand up this morning but doesn't want to, keeps laying back down and refuses to drink a thing. Think it's just too weak and small to make it.
I don't know what else can be done for the poor little thing but leave it alone and see what happens. I'll post an update later with any changes.
Again thanks to everyone!