It was a stressful day, but I think it turned out as best as it possibly could.
I couldn't coerce my horse in the trailer without feeding or working/upsetting him (two things I was instructed not to do). So ,my (amazing) vet already had a back up plan. She, another vet and two vet student interns rolled up to the barn with the ultrasound. The other vet, whom I had never met, we very sweet but I nearly cursed when she said "this is such a fascinating case." I was all "oh no sweetheart, this is scary, not interesting!"
But anyhoo. They gave granite a really cool hair cut (bless his pea pickin heart). And ultrasounded his lower belly (the suspect of much of the pain). After lots of srunched noses and Hmmm and Ummms. The verdict was that there were no foreign bodies in his tummy. But there appears to be a torn abdominal muscle, swollen spleen, hematoma, and a possible bruised rib. She pulled more blood work to be sure that nothing else had come up since monday. She did another rectal exam and the only thing she could feel was the swollen spleen, everything else was normal back there.
We are guessing he was kicked or wiped out reallly hard playing in the pasture or fell ON something (rock or stump or something). It started fairly mild so perhaps it got worse while he was playing in the pasture.
Either way we are doing some strong antibiotics to prevent abscess, low-dose ulcerguard and banamine. Oh yeah, and 6 weeks restricted turn out (in a small lot, by himself). He gets more antibiotic shots on Monday and then a re-check with the vet on Friday (assuming the second blood panel comes back normally).
I'm SUPER broke after these two visits and meds and the like but this is basically the best possible scenario. No surgery or lingering/reoccuring issues. Just G being a goof-head and hurting himself.
He was such a champ today for the whole thing. Very patient and tolerant even though he wasn't feeling good.
I'm just glad that I think (hope) that we have our answer and my boy will start to feel better soon.
Thanks for all of the suggestions and mostly the thoughts and prayers. I think I will actually maybe get some sleep tonight and not have nightmares of waking up to my horse being dead.