My Scottish Terrier has never picked up a chicken, but he does catch wild birds in his mouth. Odd I know, but he does it, and has become very good at it. Anyway he will bring them into the house lay down with them and just lick on them between his front paws. He has never once hurt one, I mean no broken bones, punctures, anything. Just a wet little bird chirping at him. When I hear it I will pick up the bird, and they are like your chicken, heart going a million miles an hour, heavy breathing, all that. I take them outside, dry them a little in a towel, and in a matter of minutes they are calm, and when they are ready they will perch up on my hand and fly away unscathed. Funny thing is I think there is one bird has been caught multiple times, I think there is a little cross species love affair or something. In the month we have had our chicks he (nor our other dog) has never ever tried to catch a chick. We introduced them from day one, so they are just family now.
Point is this. Maybe the dog just wanted to play or just has a bird fetish. Could be there was no intention to eat your little one (which sounds to be the case). If a dog had intended to kill it, it would have with it's first bite. Still a scary event for a chicken, even if the dog had "good" intentions. Hope the little one is OK now.
