Good news!

My vet sent two CDs to Cornell. The vet there was able to open one, and one CD wouldn't work. Guess which one was River's.. My vet attempted to email it yesterday. I haven't heard from her, so she was probably successful, lol.

Farrier came out yesterday. I explained what had been going on, and before he even took a look at Riv, he said he didn't think it was an abscess. Looked at him, absolutely no indication of an abscess. If my farrier says no abscess, then there's no abscess. He palpated the leg and said he thought it's an interosseous muscle injury. I got my vet on the phone and he talked to her for a bit, and they're in agreement that the problem is the interosseous muscle. Farrier said he's seen quite a few horses with this injury in the past few months.

Unless Cornell has another idea or he worsens, we're treating for an interosseous muscle injury. It's not an absolute 100% definitive diagnosis--that would require a trip to Cornell, which would just aggravate the injury. The diagnosis makes sense and my vet and farrier are both in agreement, so I feel confident that we've got a good answer.

He'll be on stall rest for 3-6 months, and when it's healed he'll be back to normal with no lasting issues.

Even if he does need the the full 6 months of stall rest, I can deal with that. It's not like we're missing out on any big shows or anything... The important thing is that it will get better and he'll be fine.