A lady at the feedstore told me that they are the same thing (and they were out of Terramycin), but on the Duramycin-10 package it says that it is for respiratory diseases (CRD and that sort). My chickens have fowl pox, and I read on here that I can give them Terramycin to help them fight it, so I am wondering if the Duramycin-10 does the same thing.