Have 4 chicks in a brooder box. Temps are cooler at night so I increase temp of brooder. They are 1 week old. Noticed 1 is getting pastey butt. I've been cleaning it of course the feathers are of its bottom now. Any suggestions ?? This is my little paint silkie that I have wanted so bad.. Lost 1 I had under a hen that started with pastey butt. Please any advice would be appreciated.