4 week old chick has something wrong. Please help!

[FrahmChicks217]

I checked on my chicks this morning (10 of them including the one that is not ok are 4 weeks old) he was fine and acting normal when I went to give fresh feed and water. Less then 2 hours later I heard a weird noise, went to check on them and he wasn't coming to the door of the brooder like normal. And wouldn't come up to my hand either. I did notice some blood, just a very small amount on a few pieces of shavings. I checkdd him over for wounds and i cant find any spots with blood, which would be easy to see as he is a cream color. He had thick saliva, shaking head, very lethargic. I have him isolated now, but he will randomly stand up, lack of coordination almost, shake his head, mouth gape and then lays back down and closes his eyes. I've checked along his throat for any obstructions, even looked in his throat as best as I could with a small flashlight. Didn't feel or see anything. He seem to be breathing just fine though. Im wondering if he smacked his head on the top of the brooder, or ate something that irritated his throat? Crop is empty at the moment and I can't get him to drink any electrolytes I'm offering via syringe to the corner of his mouth. All other chicks are behaving normally. Eating and drinking just fine. I do know for a fact he ate and drank this morning. Any one have any thoughts? Im worried I'm going to lose him, and honestly, he is a favorite and he is extremely friendly and docile. Im just guessing that its a boy at this point too. As he is an EE and to small and young to tell yet.

 

[FunClucks]

Any blue or green areas beneath his skin? This can indicate bruising. He could have taken a fall, or gotten beat up, but if there's no blood, a fall or injury is more likely than an attack from other chickens, IMO. Could he have gotten stuck somewhere or eaten something he shouldn't have? Any potential for poison or small nails in his area? Could a small child have squeezed him too hard? Could be internal injuries for that. Just random guesses here.