My horse had been fighting an abscess from a hot nail placed too high. Her front right leg had a lot of swelling. The abscess finally popped on the coronary band and I thought we were good and now my mare's butt cheeks on both sides have a lot of swelling. The swelling is worse around the top of the butt on the left and right sides both butt cheeks but also travels down swollen into the top of the hind legs. I have never seen anything like this before. I have not called the vet yet. Is this related to the abscess or does it have anything to do with recent vaccinations ( about a month ago)? No vaccines were given in the butt. The timing is more coinciding with the hot nail and the abscess that burst through the coronary band. When the farrier put the hot nail in my mare was in obvious real discomfort pulling back and making a noise, the pain was obvious, and I mentioned to him I thought the nail was too high and he said it wasn't. Abscess was not until a couple weeks later with a swollen leg and it burst on the coronary band right above the hot nail. So is this problem with a very, very swollen butt on both sides somehow related to this hot nail, but the hot nail was on the FRONT hoof not the hind? She just burst the abscess about 5 days ago. Trying to figure this out and how to treat. Has anyone seen anything like this before? Can you help with any advice? Also, I am now uncomfortable with having this farrier back. Any advice? I am getting really concerned about this and will inform my vet tomorrow.