When DJ and Junior got sunburned last year, our vet gave us a medication called "pink lady." He swears by it for all kinds of minor wounds, and it is FANTASTIC on sunburns. DJ was burned all along the top of his back, poor guy. The pink lady had it practically healed in a week, and he was rideable in two weeks.
You can order pink lady online, you don't have to get it from a vet. It has zinc in it and forms a protective barrier to prevent the bured area from burning again while it heals. Its a little pricey - we paid $15 for a small bottle, but that bottle was more than enough for the two horses.
We kept the pink lady on the areas most prone to burning the rest of the summer - it worked better than sunscreen, but the guys may have been a little embarrassed to have so much pink on them!
Plain Old Dee, horses Dancer and Rain I believe in dragons, unicorns, good men and other mythical creatures!