Still working on that abscess...

Rio was "diagnosed" with an abscess in his right front foot about a month ago (we first noticed signs of lameness on May 7th). At first my trainer said it could possibly be an abscess, then the farrier came (on May 15th) and checked and was able to drain a small amount of "black goo" out of the frog. Then my horse had on days and off days. Some days he looked almost sound, other days he was head bobbing on the lunge line. We had a good 2-3 days of soundness, and then we did some small jumps in the grass field, and the next day he was off again. 

Finally, I called the vet and on June 5 he said that he was 90% sure that it was an abscess and told me my horse is 1/5 lame (whatever that means). I am supposed to give him 1-2 grams of bute (depending on what he looks like that day); alternate sugardines and anamalax poultices; and I am allowed to keep him in very light work so long as he's comfortable (i.e. short times on the lunge line, and just walking around the ring with occasional trotting if he's in the mood).

We've been really diligent about doing all those things and I've even done the occasional Epsom salt hoof soak. Here are some photos of what his foot looked like this morning. Could this possibly be the abscess coming out?

Here's a photo of the "suspected area" from June 6, 2012:

Here's what it looked like this morning: