One of the MOST important things to know about chickens and turkeys is that they are considered major species when it comes to food production. This means there are very limited medications allowed by law to be used in chickens and turkeys, and that extra-label drug use (ELDU) is typically not allowed. ELDU is ANY use other than that specifically listed on the label (higher, lower, more or less frequent) and results in either increased withdrawal times or the removal of that animal from the human food chain (including their eggs).
PLEASE talk to your veterinarian before using any drug or chemical on your poultry, unless it has a specific label indication for your specific species, and you follow the label precisely. This includes medications/chemicals given orally, topically, by injection, or added to water or feed.
There are resources to help your veterinarian determine which drugs can be used in poultry to prevent their loss from the human food chain. Although much of backyard poultry is considered “pets,” and would not be eaten, the hens are usually kept for their eggs. Misuse of medications/chemicals can result in eggs that are unsafe or illegal for humans to eat.