Out of courtesy, you should discuss with any equine professional envolved in your horse that recommends a shoeing treatment. If you disagree with their suggestion, then voice it. Your recommendation for farrier treatment should be discussed with the customer. This includes what you will do and what you will not. Legally, you are responsible for any farrier work your do wheather the veterinarian or anyone else recommends it. Legally, you are not required to follow the veterinarians farrier recommendations unless you are an employee of the veterinarian. In the end, develop ethical shoeing of what you will or will not do in situations and always rememeber, you are legally responsible for all you do to the horse.
If you know the vet, tell him your idea, and you might figure out something between you. If you do not know him well enough to work together, then I would try what the vet wants and see if it works. I have found that the owner will side with the vet before you. If the vet's way doesn't work, then try your way.
I would explain to customer that I feel it won't help the horse, would talk with the vet and get his input about x-rays, exams findings, etc., then go from there... offer maybe another way of shoeing the horse...don't leave anyone out of the information loop!
The area that I work in I seem to have a good working relationship with all the vets in my area, so I would call and try to add my two cents in and see what common ground we could come to in helping the horse.
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