One of my new quail chicks was born a runt and had trouble walking. I worked out that is was due to a vitamin b12 deficiency. I separated him from the others so that he wouldn't be knocked over and gave him the extra vitamins he needed. Over the week since he hatched hes been slowly getting better. But all of a sudden hes staring at the ground, running backwards and falling over. I have no idea what the issue is and cant seem to find an answer that fully explains it and if there is anything i can do. Heres a link to a video of him.