lost 4 of my 3 yrs old hens to some virus? help

[chickenwhisperer16]

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.

 

[seminolewind]

Have they eaten anything bad? Is your feed okay? If they have a respiratory thing, Tylan might be worth a try. If they had a virus , where would they have gotten it from?

 

[chickenwhisperer16]

Thats just it, They pretty much started getting this way when spring came along. I buy Layenena feed for them. Purina scratch grains and they get bread or other left-over veges from the house hold. They have never had anything like this at all. Its just horrible to see this happening to them. I have had this coop in the same spot for 3 yrs now. I clean it every other day and scrub their water holders down with a water and bleach mixture to kill any thing that might be causing this. I let them run for 2 to 3 hrs out of their pen to exercise but nothing different than usual. We clean the poop out of the main pen every spring and put new dirt in so everything is fresh for them.
I was told by one vet that it might be respiratory but he couldn't be certain until he was able to examine a dead chicken for a price of course. I really don't have the cash to give a vet right now, but I really don't want to lose anymore of my hens. So, I'm trying to see if anybody out there has had any trouble like this and what they did to over come it. This hit my oldest hens first, now its starting in my 1 yr olds. atleast one of them. She doesn't seem to be as bad as the others as this point and it might be because I've had them on antibiotics for about 2 wks now. I was hoping to get them off of the antibiotics and wait 2 more wks to start enjoying their fresh eggs again, but now I don't think thats going to happen.
My father-in-law likes to feed the wild birds thistle seed not to far from my chickens and I also thought that might be the culprit but we had all that moved and raked up and its still happening. We do have a lot of baby frogs this year and alot of wood ticks. Can any of these things make a chicken so sick it dies? I'm going to try Tylan. I go to my Co-op in my area , so I'll see if they carry it. Thanks