The one time my vet suspected a *possible* clostridum infection she prescribed metronidazole twice a day for 14 days. I think the actual dose was around 50mg/kg twice a day. My hen also had a gram negative infection, so she also prescribed Baytril.
-Kathy
Can you get those off label? I don't have a vet that will have anything to do with poultry.
You can get just about any antibiotic for fish. Look up fishzole, that's metronidazole.
-Kathy