Tech and supervising vet examined him. Supervising vet has been a professor at Cornell for 38 years. He's never seen something like this and does not know what is wrong.
The only palpation/manipulation that got any response was when they pressed on his shoulder with one hand and pulled his withers with the other. Then he said "wtf, dude, that hurts, stop it!" Neither vet had seen a horse who reacted only to that. (Not sure if he's the only horse who had reacted to that, period, but definitely the only one who practically napped through having his leg pushed and pulled and twisted and flexed, and then reacted definitely to the shoulder-wither push-pull thing.)
They blocked his foot, just in case, and as expected there was no difference.
Generally, the next thing would be to block up the leg to pinpoint where it hurts, but because of how lame he is (4/5), there's the definite possibility of a hairline fracture, and we don't want to risk a hairline fracture turning catastrophic because he couldn't feel it to be careful.
So they recommended a bone scan. I said okay, let's do it. But wait, we can't do it today! Or tomorrow! Or the next day! Or the next day! They have to request the radioactive stuff 24 hours in advance, and it can't be done on a Friday because the specially trained/licensed people have to check him the next day to be sure he's no longer radioactive. The one vet did actually check to see if there was any way to get it done sooner, but unfortunately no. Monday would be the first available.
Talked to my vet.... well, I had the Cornell vet call her and discuss it with her first because I was having a mini breakdown. Talked it over with my vet, and decided to leave him at Cornell until they can do the scan. As much as I hate to pay $100 a day for board (!!!!!!), I couldn't live with myself if I decided to take him home and bring him back, and he suffered a catastrophic fracture on the trailer or at home.
So River is spending a long weekend at college, living in the dorms. He very quickly won over his team, all of whom think he's a very sweet, cool, handsome horse who is very tolerant of all the poking and prodding him.
Before I left, they asked if there was anything they should know about him.. I told them he loves peppermints and cuddles.
They'll call me every day to let me know how he's doing. They'll do the bone scan on Monday, starting with his shoulder and elbow and working their way up and down his leg until they find something. If all goes well, I can bring him home on Tuesday. If the bone scan doesn't show anything, the next step would be to start blocking up the leg.
Riv's definitely gone all out on this one.. even a vet who's been a professor for almost 4 decades doesn't know what's wrong.