It is infectious coryza. You can treat with antibiotics such as Erythromycin, Dihystreptmycin, Streptomycin sulphonamides, tylosin, and Fluoroquinolones.
I have had cochins for years. They are perfect for the owner who is very attentive to their back yard flock. They are very gentile and almost enjoy being handled. Beware! Everything wants to eat a chicken and these chickens are not good at escaping predation. I purchased mine as chicks from...
I have two older chickens, 4-5 years old, that have lost their balance. Both the rooster and the hen still have an appetite. Rooster constantly flapped his wings. He has nearly recovered. The hen just came down with this. Her wings became droopy then she stopped roosting. Any ideas what it could be?