Talk to your vet. It might not be scratches if it’s not clearing up, it might be an allergic reaction or reaction to a toxic plant.
I’m going through this now with my horse – on occasion his pasterns swell up and he gets crusties that are not quite like scratches. One of my vets prescribes Dex in his feed, but the other prescribed Otomax (which is an opthalamic treatment for dogs, has a number of drugs in it), rubbed in once a day, which worked just as well as the Dex.
Seeing just the other day he swelled up in front of his sheath this time, and the otomax still worked… I suspect there’s a not very common plant in his field that either he’s allergic to, or that’s toxic, and causes problems when he touches it. So far, I’ve not been able to find the culprit.
Proud Partner of Yankee Allstar,
Rocky Mountain Gaited Horse