Hello. Sick chick hatched 4 days ago. Today a water like area appeared on its back near the tail. Down has fallen out or been pulled out. Chick is in a brooder box made of a plastic bin, heat lamp, paper towels used as floor covering. Food = chick starter. Water with vitamins and electrolytes. One of 25 that hatched from 41 eggs shipped mail order. Only one with fluid filled bump. Please advise on possible cure. Thank you.