I was thinking the same thing Robin, most skin infections are staph or fungal so an antibiotic or antifungal injection/pill may help. Can they scrape it and culture it to see whats growing there? When my horse had scratches, I treated her with silvadene an ointment used to debride and treat severe burns in humans since most of their infections are staph infections it worked very well with the scratches. It was very expensive but to me worth it as it cleared up in a few days.
