start them on tylan 50 dose is bantam 1/4 cc once daily for 5 days, larger birds 1/2 cc once daily for 5 days. on the bottle it will read for cattle and swine not to worry its used by many many poultry owners including myself for respitory problems
in my opnion better than water soulable antibiotic because it's higher concentration and dose is controlled. problem with water soluable is when they are ill they don't drink as much as they need to usually and the dose is not consistant. there are two places to give the injection, nape of neck or breast. if you have never done it, you tube had some great instructional videos on how to do it. please start there tylan as soon as you can.keep us posted on how they are doing. don't freit about giving the injection,its easier than you think. the hens will thank you for it. Hope this is helpful. you can find tylan at feed store
best of luck!