Poor horse has a huge fly bite on his back. Doesn't seem too bothered but it's right where the saddle sits. Obviously didn't ride today but any tips on getting it to shrink? It's about the size of a walnut!
Aloe Vera, cold tea bag, anything that will take down the swelling. I wouldn't ride for a few days. I had a few last year, massive and horrific, but only for a couple of days. You can probably get cortisone 1% cream at the pharmacy which would be a massive help.