I have a 4 month old pullet, she has 3 siblings they are American game, towards the first of the week she was making noises like she had something stuck in her throat, so we checked her out no impacted crop, and nothing logged in her throat. she walks around with her mouth open like she has a problem breathing yet she doesn't seem to be in distress. She was still free ranging with the other birds and eating and drinking, I did start giving her some baby vits by mouth but still no change. well this morning when I went to check on her, she can't walk well her foot is drawn up and there is no visible sing that theres anything wrong with it, still breathing with her mouth open. No other chicken is having this problem. Her eyes are clear and no discharge from her nose or anywhere else. looks very healthy. I am at a loss to know what to do for her other than to put her down. I would appreciate any help anyone can give.