I have some oxytetracycline to put in the water and injectable penicillin but my local feed store doesn't carry the one that starts with the "t" I forget but by cull you mean what I think you mean right
Oxy would treat a respiratory disease. Do you mean Tylan--that is one of the best drugs for respiratory diseases, and is available by injectable (Tylan50) and as a powder for the water. It is a cattle medicine, so most farm stores should have it. Cull means to kill, sell or re-home, but in the case of sick birds it means to kill them. Burying very deeply or burning the carcasses is best for not contaminating your soil. Sorry you are dealing with this, but if I had a healthy flock already, I wouldn't want to risk making them sick.
Thanks for the info and yea I meant tylan. My local feed store stopped carrying it because no one was buying it but I got some Oxytertracycline and started them on that today and sprayed them with permethrin for the lice and mites. I am keeping them in their own pens separate from my yard birds and have treated the areas they where with a bleach mixture to tye and prevent transmission but I have them where my other birds do not go so I hope this works and I am not exactly sure what they could have but it is respiratory :-(