Injured chick? Or just poo?

[Erinjmiller]

Hey ya'll! I am brand new to the group and especially new at raising chickens. We are on our third week now and have two groups - 3-week old barred rocks and 1.5 week old ISA browns. Our browns have been together and fine since day 1...until today. Our smallest one seems to have something on her back and on her wings, but I can't tell if it's just dried poo, or if it's blood. Below her wing, her down seems to be pretty crusty. I am watching them right now to see if the larger girls are picking on the little one, but so far, they are behaving. I took some photos. Any idea what this is, and if it's an injury, any idea what I should do? Separate the two smaller ones? Clean the smallest one or just let her be? Any help is much appreciated!

 

[Wyorp Rock]

The only way to know if it's poop or blood - give her a wash up so you can see her skin for injury.
Dry her well before going back into the brooder so she doesn't chill - you can use a hair dryer to dry her - use a low setting and careful not to get too close to the delicate skin and burn her.

Keep us posted.