I looked up tetracycline and found it at wal-mart's website as a medication for fish. Is that it?I have never used anything not formulated for poultry, so I don't know whether amoxicillin will be okay. I usually get one of the tetracycline meds at the feed store, it takes some calculation to get it down to what to put in 1 quart or 1 gallon, but I can usually get it close, and was recently told if you treat with antibiotics don't go low or middle, go to the highest dose recommended for poultry, so you don't risk creating resistant bugs.