Furazone is now known to slow healing and promote proud flesh. It shouldn't be used on a leg wound. Rather a plain triple antibiotic ointment is recommended for most wounds by the veterianarians who are involved in wound healing studies.
If your bandage is slipping, you need to have your vet out to show you how ot wrap it so that it won't. And if you aren't confining your horse to limit movement you should be.
Wonderdust is a caustic substance and needs to be used with care. Caustic substances will destroy any tissue they come into contact with--proud flesh or normal, healthy tissues. For this reason, they can slow healing and should only be applied to proud flesh. In a wound where proud flesh is just starting to form, a better choice is to use a combination of steroid and antibiotic cream. This will ****** the formation of proud flesh without damaging the normal healing tissues.
It sounds like you need to have your vet out to recheck the area and show you how to bandage it so that the bandage won't slip and possibly get you a cream to prevent proud flesh.
Licensed Veterinary Technician