Both my gelding and my mare have these small scaley like spots on their belly and their back that are covered in small black flies. Can anyone tell me what it is and how to get rid of it. I have been putting mtg on it but it just comes back.
You may want to go with more of an anti-fungal/antibacterial cream.
I mix up anti-fungal athletes foot cream and triple antibiotic cream together and use it for thrush and any skin problems. If nothing else use something like Tricare 3-way ointment or Swat. They are an antibiotic that will also keep flies away.
I agree with Vidaloco, you need to use something else because what you are using isn't working. ;) I tend to use Desitin baby butt ointment. Works great on rainrot, fly bites, and about any other lil ouchy. It shields the area from pesky flies too.