Ok I have chickens that are sick (sneezing, coughing, and you can here there chest rattling when they breath) and we bought some medicine for them its called oxytetracycline. It says its ok for poultry but not to give it to chickens that you use for eggs. So is there any medicine that we can give them that it will still be ok to eat there eggs???? Also my chickens are different ages and sizes. (young silkies to adult rhode island reds) We have a tractor supply here that has Injectable Tylan and we thought about using it how much do we have to give them? Where do we inject them? How much do we give them? Also if we use injectable tylan will it still be ok to eat there eggs?