I have a chick apx 8 weeks old, at 5-6 weeks of age I noticed it wasn't walking and getting around like the others were, I separated the chick and quite frankly didn't expect it to make it, but it is still eating and drinking and thriving actually except that it shakes when it walks, I wouldn't call it paralysis, just shakes? What do I do? I have quite a few chicks hatched at the same time so I don't think its merricks or more birds would be effected? Help? I gave vitamins B-12 in water and by mouth and didn't notice a change...Should I cull it?