I posted this in the emergencies category but no one responded so I'm going to try here. In the past couple of days 2 of my 5 wk old pullets have become weak in the legs and can't walk. They can stand unsteadily but when they walk they fall over. They are otherwise healthy and all of the rest of the chicks are fine. They are still eating and drinking like normal and are showing no other signs of illness. One is a Black Sex Link and the other is a Buff Orpington. They are both pullets and they are on a commercial chick feed with 20% protein. The feed is not medicated. I thought maybe these chicks had a nutrient deficiency so I seperated them from the others and fed them a mix of chick feed, yogurt, fish oil and boiled egg. They ate it like it was going out of style but they don't seem to be any better. What should I do?