This is a tough question to answer sometimes. There are often times some outwardly visible signs, such as stretched lamina and founder rings on the hoof, to name two, but the best founder detection tool is still the x-ray. X-rays are a vital tool in determining the certainty of founder, because they allow us to see the bone alignment inside the hoof and determine if there is any deviation from ‘normal’. Since Superman is no longer with us, no one, including the best vets and farriers alive today, has the ability to see though a hoof and see if, or how much, the coffin bone has rotated. All that can be done for sure is suspect there is rotation. X-rays are not perfect, by any means and they are only a single point in time. They are only as good as the person setting up the horse for the x-rays and they are only as good as the x-ray machine capturing the x-ray image. This is why new methods of viewing the inside of the hoof are being developed, but for now, x-rays will have to do and we have to hope for the best each and every time new x-rays are taken.
After x-rays are taken, it’s not hard to see if there is rotation of the coffin bone, but it does take a trained eye to determine the exact amount of rotation and to determine if there are other factors internally to that foot and body that will need to be taken into consideration before a treatment protocol can be developed for that individual horse. Rotation of the coffin bone isn’t the only issue important to determining severity of the situation. Re-modeling of the coffin bone, position and stress on the Navicular bone, health of the back side of the coffin bone and alignment of P-1, P-2 and P-3 must also be taking into account before determining an initial trim protocol. This is why you need good x-rays and you need to employ proven founder specialists to help with prognosis and recovery.