Sick 6 week old

[AnniesEggFarm]

Hello...
I have a wee little flock of 10 chicks. This afternoon one has become weak, crop is full of, I assume water, & staying away from the rest of the flock. They have been out in the yard foraging for the day and everyone else seems fine. I gave it some apple juice with probiotics in it, but just seems to be getting weaker. Any thoughts.

Thanks,
Jenn

 

[AnniesEggFarm]

I should also add it had some loose stool.