PLEASE HELP!!! Does this sound familiar? Vet's don't know what is wrong.

Is he still eating well, losing weight or running a temperature? These things will tell you is the infection is spreading. Did these vets take a blood sample? Were these vets who specialized in equine medicine or small animal vets who treat a few horses on the side? I'd say for another opinion go to an equine vet specialist or as others suggested a teaching college. Also were either of these the vet that gelded your horse?