This happens with my friends horse Woody after my friend currys him he gets like rain rot or something!
Thanks for the response! I wash my brushes very often and it doesn't make a difference, so I don't quite think this is it. I'll mention it to the vet next time she comes around, but as it isn't really a "problem" per se- it doesn't bother him, he loves being curried.
This happens with my horse too,normally if I wash my curry really well and let it dry then he doesn't get bumps if that doesn't work then I would just ask your vet to confirm