 Fortunately, foot rot is pretty easy to treat, so there is a whole list of antibiotics, ointments, and salves that you should discuss with your veterinarian about using to treat foot rot. Livestock-grade penicillin seems to work well as long as the problem is observed and dealt with early. If the localized infection has been there for a while, when you notice it, you will probably need something with a little more punch to it.