Hoof Sole Quality

 

Sole quality is one of the most difficult points for the non-farrier to assess. Sole should be resilient: neither too hard nor too soft. Sole that is too hard tends to crack and flake. Sole that is too soft is easily depressed by a sharp external object such a rock or by the force of the coffin bone from the inside.

Depth of sole is an indicator that can only be absolutely determined by an x-ray. Indicators of sole depth are not easily described. When a foot has too much sole farriers describe it as retained sole, also called false sole. This means the foot fails to exfoliate excess sole. Feet that are too short will have the opposite problem as they lack depth of sole. This is a difficult problem to correct.

This freeze dried specimen is trimmed on one half, showing the different appearance of retained sole (right side) and true sole (left side).

One sign that may indicate inappropriate depth of sole is bruising in front of the tip of the frog. This can be easily seen on feet that are too short. But if the feet are too long with retained sole, bruising may not become visible until the farrier begins to remove the outer layer.

Sole bruising commonly appears as a crescent shaped red or yellow ring on the sole in front of the tip of the frog. This is in the distinct shape of the coffin bone. A sole most subject to bruising is either overly arched, extremely flat, or the laminae fail to hold the bone securely in the normal position within the hoof capsule.

This photo shows a coffin shaped bruise in front of the frog. The rest of the hoof looks healthy. The white line has no stretching or bruising. The cause of this bruise may be the hard retained sole this horse had before being trimmed.

You often hear that thin soles lead to bruising. While this is probably true, the horse in this photo is an example of bruising on soles thick with retained horn. If the sole is too thick or too stiff to have any expansion and flexibility, bruising can result from the coffin bone banging against the unyielding sole. As the horse moves, the bones in the foot sink down toward the ground. There must be some resiliency inside the foot to allow for this movement.

Often, sole bruising occurs in horses that never set foot on hard ground and do not come in contact with rocks. For example the term “stone-bruise” is used by some people at a racetrack to describe a crescent shaped bruise in front of the tip of the frog. There are no rocks on a race track so the likely cause of this bruising is the force of impact of the coffin bone against a sole that is not able to bear this load.

Another type of bruising commonly seen is in the white line and/or the heels. This type of bruise is visible once the shoe is removed. A shoe that is pressing against the sole sometimes causes bruising along the rim of the shoe or in the heels where the white line bends inward to form the bar.

Gait abnormalities such as imbalanced hoof landing can cause sole bruising from excessive force on the feet. If your horse has sole bruising it is a warning sign that should not be ignored!

 

Copyright © 2012 ~ Dr. Lisa Lancaster DVM, WDAA Blog Author

 

One Response to “Hoof Sole Quality

  • I enjoyed reading this blog. I have Morgan horses who are barefoot almost all the time. I put shoes on if I am going to ride in rocky country or if I am going to a show. I would love to learn more about trimming young horses, from foals on up, so that any problems can be mitigated or eliminated. Thanks for this great article.