hi,
just though id say i also had a youngbird that lost the use of its legs within a few days of being split off from the parent birds, it also lost the feathers just under its chin, droppings were fine under the mic, and no sign of canker ect so i gave it calcium and withing a few days it was a whole new bird the feathers came back in and it was perching and exersizing its wings and its never looked back since ;D no clue really what was wrong with it tho its been the only bird to show that kind of symptoms to im hoping it was just a mineral deficiancy