Join Date: Jan 2008
Location: British Columbia, Canada
Am I understanding that your friend HAS had the horse looked at by a qualified equine vet? If so, she really needs to get a second opinion. If as Ryle has suggested, going to a teaching hospital or larger equine hospital, is not something she can do, she may be able to get some good recommendations from other knowledgeable horse people in your area. Ask around at local feed stores or tack stores. Most of the people that run these places have horse's themselves.
If the horse is in that much pain and a vet can not locate the problem, then that vet is a problem.
As for what could be wrong...... geez where to start? It could be any number of things. Poll, neck, shoulder, back...... and it goes on.
As Ryle has suggested, a full work up with any or all, nerve blocking, x-ray's or ultrasound is going to help pin point the problem.