Is your Vet an equine specialist from a large equine center or is your Vet a 'country Vet' with a mixed practice?
If you have a country Vet, it may be time to call an equine specialist. The equine specialist we call for tough things has a portable x-ray unit that shows the x-ray on a computer screen about 30 seconds after he take the shot. He does the tough stuff. Our country Vet does everything else.
But, to put things in perspective, our country Vet charges a $60.00 call charge (comes 20 miles) and castrates horses for $90.00. He also spays out dogs or cats at his clinic. He is an excellent cow Vet and works on our bison. He actually raises bison.
The Equine specialist works out of a big clinic with full surgery facilities that is 75 miles away. He only lives 30 miles from us and only charges $100.00 for a call. But, he gets $350.00 to castrate a colt. So, I call him when I need x-rays or am completely stumped on something.
I think you need the equine specialist. Most charge a lot less when you bring the horse to their clinic. If you have a big training or breeding center near where you live, call them and see who they recommend that is an Equine specialist or works out of a big Equine Clinic.