My horse also currently has an abscess that's refusing to go away.
A week before Thanksgiving he came up 3-legged lame and after soaking that day and an epsom salt poultice overnight, it appeared to have drained, though he was still a little sore so I soaked again, applied another poultice overnight and then continued soaking for a few days after that. I also limited him to indoor (dry) turnout only.
I was supposed to have a lesson 4 days after he originally had the abscess, and he looked perfectly fine when I put him through w/t/c on the longe line beforehand and walking under saddle, but when I got him up into a trot it was pretty obvious that he was still sore. Back to soaking.
Two days later was his regular farrier appointment, so I had him check to see if he could find it and dig it out, but there was only one slightly suspicious area near his bars which was a little chalky and easy to scrape away, and the farrier didn't think it was suspicious enough to try digging too deeply into it.
This past week he again seemed fine on the longe line, and even under saddle, so I rode him lightly on Wednesday, walked him around a bit on Thursday (mostly just to give him attention as I was riding another horse that evening) and there didn't appear to be any trace of soreness left.
Then yesterday I met someone at the barn to drive together to a clinic I wanted to audit and he was 3-legged lame again!
I waited until after coming back from the clinic to soak him and wrap him up again, and by the time I got back he was noticeably improved already. I soaked him and wrapped him up anyway.
I figure I'll soak and wrap him for the next week solid, whether he looks better or not, and hopefully that will draw out the rest of the abscess. If not, I'll have to get my vet to see if she can find it.
Abscesses are no fun :roll: