have isolated a stock hen today, this morning she fed with the rest seemed OK, went in the loft this evening and she was lying in the corner of the floor she could flap her wings but legs seemed like paralysis she seemed alert enough her cock I killed on sat with the same symptoms she was still feeding 1 youngster and that was only her 2nd nest.? any help would be appreciated.the vets in this area are not to good, they just guess the same as me.