young chicken with liquid coming from beak?

[KrisC]

Unfortunately for my first post its about one of my barred plymouth rock chickens. I brought him inside to check his band to make sure it was not too tight and after removing it, I was holding it to make sure it was calm, and suddenly found myself covered with a clear watery liquid. he isnt showing any other signs of sickness. alert and moves around. though as of now he hasnt eaten since bringing him in.
I have about 25 other chickens, and im unsure if they are affected by this-it was getting dark when i brought him inside. I am worried about the chance of some of the chickens dying because several belong to my children.

Is there any way to discover what this is and how to treat it? I dont have a vet in the area skilled with chicken care, so if it needs medicine i would have to get it online. is there anything safe to give the whole flock? some of them are meat birds I bought for butchering.

I would appreciate any help. ty in advance.