OK, try short soaks in betadine(covering only his feet) and then rinse completely. Make sure he doesn't drink it. Rub a thin layer of triple antibiotic ointment all over his feet (you can get this at any pharmacy) I would dry dock (put him in a dry container)after for a 30 minutes after the soak and then keep his water very clean. Do this 2 times a day. Look at your temps also. Keep the water at 70-74 degrees and the basking area at 85-90. This should encourage him to bask which should prevent the problem from re-occuring. Is spite of what many people think, they do best without a water heater if a room is kept at at least 70 degrees.

Good luck and give me an update
Linda