I have a mixture of 3 yr old hens and 1 yr old hens. The 3 yr old hen started looking like they did'nt know where they were and walked slow practically with their eyes shut doing some quirky thing with their necks. In a day or two they started leaning down to take a drink and fluid was running out of their mouths before they even got to drink anything. I picked up my Buff orphington and she spat fluid everywhere out of her mouth and it stunk. I put her down so I wouldn't drown her from her own vomit but she never got better. I put them one by one in a cage with antibiotics , but I finally lost 4 of them. After losing them 4 I put all the rest of the hens on antibiotics,(Duramycin-10 ) 4 tps. to a gallon of water. I have downed the 4 tsp now to 2 because i am almost to my 2 wk period of having them on the antibiotics and I thought it would be okay to do that, but now I have a 1 yr old showing the same signs today. 2 days shy of 2 wks on antibiotics. I couldn't believe it. The vets around here know nothing about chickens so I'm on my own. I've been just reading on this site and others to find out what is going on and how can I stop my chickens from dying . I feel like I'm running out of time. Should I use a stronger antibiotic? What the heck is this stuff-virus do they have? Does anyone out there have any answers? Please help.