I got 5 buff orphingtons one week ago yesterday. They were about 3 days old when I got them. A few days ago, I noticed that one of the girls was kind of gasping/panting when she breathed. I wasn't too concerned at first, I just figured she was hot and would move away from the light. Last night I noticed that she was moving a little slower than the rest of the girls. This morning, she was kind of laying on her side and when I stood her up she wobbled and fell over. Now another one is starting to show the same symptoms. I gave them some vitamins and they seemed to perk up a little for a little while, but now the worst one of the two is doing the same thing again. Any idea what's wrong and what should I do???