Anyone who works in poultry or livestock health has seen a single water medication that lists doxycycline hydrochloride, colistin sulfate, and florfenicol together. On paper it looks like three drugs doing the same job. They end up in one bottle because they hit bacteria at different points, and those points happen to line up. Here is how each drug works on its own, and why the three together do more than any one of them manages alone. The three drugs, one at a time Doxycycline hydrochloride Doxycycline is a tetracycline. Like the rest of that family it is bacteriostatic, which means it slows bacteria down instead of killing them outright.…