I 've got a chick that is not thriving-infact not walking at all. It's a lot easier when they are big fat meat chickens.
You could soak two cotton balls in ether (starter fluid). Place on on either side if the beak near the nostrils until they fall asleep, then place the cotton balls totally covering the nostrils and the chick will pass away. It's the least stressful way all around that I've found. So sorry the poor thing isn't doing well.
