Originally Posted by walkinthewalk
I agree that looks like hives.
Have you wormed her in the last few days? Any meds?
Have you changed hay? Even if you haven't, has it been checked for any type of weeds or mold?
If she's on a roundbale, how long has the roundbale been out?
If she's on pasture, it's entirely possible she's eaten some sort of weed that she wouldn't normally eat because grass isn't plentiful.
One of my horses comes in smelling like wild onions every night because they are growing taller & faster than anything in the pasture and he loves them.
She hasn't been wormed since late December and she isn't on any medication. We haven't changed hay either, the pasture is pretty muddy (especially with all of the rain). We give free choice hay in the barn and the get extra hay and grain at feeding time. I guess it is possible she got into something in the paddock, but I can't know for sure. I have checked and double checked many times to make sure there is nothing growing that is dangerous to their health, but she is pretty sensitive.