I have an 8-9 year old Langshan rooster who has been progressively going downhill. He used to weigh about 9.5 #s but has been losing weight. About 3 weeks ago we discovered he had a lice infestation and gave him Ivermectin orally, bathed him and sprayed him with Frontline (Fipronel) spray (just a few squirts). He weighed 8.5 #s then. We treated all the chickens in close contact with him with Ivermectin and Frontline at that time. He is housed in a large dog crate on pine shavings with a buff hen and eats Nutrena layer pellets 16% protein and Meatbird pellets 26% protein. About 3 days ago we noticed he seemed off balance, and would take a few steps forward, then stumble backwards a few steps. He also seemed to lay down more. He has lost another #, but is eating and stools look normal. He sneezed once but does not have any nasal discharge or breathing difficulty.He constantly opens his beak and does a chewing action which is odd. I started him on Ciprofloxin (30mg/kg) orally twice a day but haven't seen any improvement. Two days after starting the Cipro he is unable to stand, his legs go out to the side or behind him and his body is emaciated, despite his eating oatmeal, veggies, scrambled egg and a little dry cat food. He still does the chewing thing with his beak too. No other chickens are affected. We have not had any new birds brought in, but a lady who raises chickens did come by 10 days ago and was over by the barn where he lives. If anyone has any ideas I would really appreciate it. Thanks.