This plane starts from the ground surface and moves up through the foot. Balance here is simple in theory but difficult to master in the practical. How short do you trim a horses hoof.? There is no simple answer to this question, except maybe in the fact that if you trim away to much of a horses sole they will be sore. If a farrier has never sored a horse in this manner, they have not trimmed enough hooves or they are taking liberties with the truth. If a previously sound horse is sole sore after a farrier has worked on it, that farrier has removed to much sole, especially if the soreness persists beyond a day or two. Every one makes mistakes, but good farrier care has soundness as both its short and long term goal. Conversely, many hooves are left to long so as to avoid the inescapable rebuke that a farrier is certain to face if the hoof is trimmed to short. This strategy can slowly begin the process of hoof capsule over growth and distortion which can appear subtle from the outside but dramatic when analyzed from the inside on radiograph. The ill effects of these distortions far out weigh those caused by over trimming when it comes to long term soundness seen in the equine industry as a whole.

The ability to read a horses hoof capsule, identify how much hoof to remove and where to take it from, is in my opinion, the most important skill a farrier develops. Many factors come to bear upon this process: Conformation, hoof type, hoof quality, disease processes, occupation, season, environment, shoe type or lack there of, and degree of capsular imbalance just to name a few.

Most experienced farriers intuitively learn to identify what has been called the live sole plane or more recently a state of uniform sole thickness. We all development our own methods for identifying and establishing this plane, the specifics of which are beyond the scope of this page. When a hoof is trimmed to a state of uniform sole thickness its essential conformational faults and attributes can accurately be accessed. In his article Uniform Sole Thickness, Michael Savoldi provides illustration of this concept and its importance. This is often the fly in the ointment when it comes to getting the job done in corrective farriery. A hoof must be addressed in its essence to understand what we are truly attempting to correct. Individuals who can readily trim the wide variety of hoof presentations to this state are in short supply within the equine industry. For this reason, many farrier plans are doomed from the start or quickly fall off track. In this practice all attempts are made to radiograph and analyze each hoof in a state approximating this ideal.

Once a hoof is trimmed to a state of uniform sole thickness I believe the essentials of balance in this plane can be determined from two radiographic measurements: the P3 distance to ground and the P3 bottom angle. The P3 distance to ground is simply how much sole is protecting the sensitive structures between the ground and the tip if the coffin bone. This depth of sole should be at least 15mm in a light breed horse. The quality or toughness of sole in this region is also important in the amount of protection provided to the underlying tissues.

The palmar angle of the coffin bone or P3 bottom angle is the second critical parameter in this plane. This parameter gives us insight into where the weak or compromised region of the horses hoof is likely to be. Again, Michael Savoldi’s diagram  makes nice illustration of this concept. Individuals with high P3 bottom angles (~>10degs) tend to be compromised at the solar toe and pedal margin and individuals with small P3 bottom angles (~< 2.5 degs) tend to be compromised in the heel and bar regions. Care should be taken not to over trim these compromised regions.