I have no idea what is going on. I just hatched out 20 chicks. They hatched over a 3 day span and all were doing fine (except one born crooked) running around and chirping the were put in the brooder with a three week old chick that has never been outside. Then the second night I went to check on them and one was dead. I was surprised but it happens. The next morning three more were dead. All same symptoms. Fine one moment then becoming very lethargic laying with wings out and finally gasping. At death a clear slimy liquid came out the the beaks. I got them all on antibiotics and gave it to them in the brooder waterer and with a dropper. Also added some electrolytes. There has been no runny poo. FINALLY yesterday the dieing seemed to stop. I was left with 8 chicks and the three week old chick. But it seemed to be walking funny. Like one side was not working. It would walk a little bit lose its balance and lay down. Today it spent a lot of time laying down and I was giving it the meds/fluids by dropper. It has gotten worse not better. It cant stand on its own and its legs seem stiff as it keeps them pushed forward. I cant fold them up unless I push a little hard. Like the muscles are tight. Its breathing like the others seems fast and a little labored. If I pull its wings out it does not pull them back. just lets them hang.The eggs I hatched out are from my chickens and no chickens have come onto my property in a few months. The last time was in Feb when I got some chicks from a hatchery. They are all fine and outside. I also have not gone anywhere with chickens so I have no idea how the chicks even got sick like this!!! Any ideas?