The Contracted Hoof : by Steven Teichman

The contracted hoof has long been a common shoeing problem and one that has been of great interest to me. In my experience as a farrier, this condition has been dealt with in several ways. The common approach is to treat a con­tracted hoof as the primary problem. This condition of the hoof may lead to more severe problems and lameness. Horseshoers have been taught to identify contracted hooves and apply corrective measures to avoid future problems caused by the misshapen hoof. Observing horses that have been treated for contracted hooves as the primary problem has led me to question this approach. The reasons for this stem from watching attempts to spread these hooves. The use of shoes with grass tips, pressure bars, and extreme heel lowering to correct contracted hooves is based on the frog-pressure theory of hoof expansion. Other shoes such as Chadwick springs, Defrays’ shoes, and slippered heel shoes are mechanical methods of spreading the hoof in the heel ·area. The results have been minimal, often resulting in a lame or more lame horse.

Another concern of mine is why these methods have remained so popular. Some have been used repeatedly for over 100 years! To discuss hoof expansion and contraction, we must have a general knowledge of hoof movement. I have recapped two theories of hoof expansion that are widely used today.

In the accompanying discussion of hoof movement, hoof expansion is critical in maintaining circulation and absorbing shock.

Therefore it is vital that when a horse is shod one does not in­terfere with this process. In the middle of the 19th century the concept of fitting a shoe to a normal hoof and allowing for expansion was just beginning to be understood.

 
In the 1913 translation of Lungwitz (1884 edition) by Adams, we have the concept of a full fitting shoe:

A shoe for a hoof of the regular form fits properly when outer border of the shoe in the region of the nail holes closely follows the outer edge of the wall, but from the last nail hole to the end of the branch extends beyond the wall a sixteenth to an eighth of an inch....

By examining these two represen­tative theories it becomes much clearer why farriers would choose to make the hoof expand. An open-shaped hoof equals a healthy hoof, and a contracted hoof equals a nonhealthy hoof.

Lungwitz’s book, as translated by Adams, owing to its age and circulation, is probably the most widely accepted theory on hoof expansion. Farriers taught with this theory (which is likely a large majority of farriers in the U.S.) would be likely to spread the hoof by lowering the heels and applying frog pressure, by slippering the shoes’ heels, or by shoeing in combination with a Chadwick spring.

Emery, Miller, and Van Hoosen view the frog as a shock absorber only, not as having the wedge effect that Lungwitz and Adams describe. This historical evidence establishes a valid reason for the widespread use and longevity of these practices. Yet it does not explain why farriers continue to treat only the hoof shape. The contracted hoof reflects a mechanical breakdown. Let’s take a look at some of the causes of hoof contraction that are apparent today.

The causes of such a problem are many and varied. Basically these causes can be grouped into (1) too little exer­cise (either intentionally or as the result of persistent lameness); (2) normal shoeing, which decreases expansion by applying a poorly expanding object (shoes and nails) to the foot; (3) im­proper shoeing; and (4) occasionally horses born with misshapen feet. For example, the branches of a shoe that are inclined downward and inward will squeeze the heels together. Shoeing too “tight” in the heels and rasping and fit­ting heels to the shoe may compound the problem of contracted hooves. In Lameness in the Horse, (1852) Percivall says “From the very moment a shoe is nailed to the hoof, the faculty of expansibility is more or less impaired. It can no longer, under the same force or weight, yield or expand to the same degree it did before.”

With this in mind, and over the course of 18 months, I examined a group of 30 horses, 20 of which had acquired a contracted hoof or hooves, and 10 of which had congenital contrac­tions. These horses were of different ages, breeds, and occupations. The common denominator was the owners’ request to treat the hoof for contraction.

 
My procedure for treatment was to:
  1. Collect the history of any lameness, recent or old.
  2. Confirm the diagnosis contracted hoof
  3. Apply corrective shoes.

The minimum requirements for all of these shoes were to provide a flat ground surface and to fit the shoe full, from the widest portion of the quarters to the heels. Bear in mind that these shoes varied to some extent. due to the horses’ occupations or special pathologic requirements.

The following is a summary of col­lected information from Table A.
  1. Horses with acute lameness, probably nonweightbearing: in this sample the affected hoof had contracted.
  2. Horses with congenital or hereditary defects (the clubbed-hoof and flexor-deformity horses): often the hoof remained contracted.
  3. Horses with this nonweightbearing condition, once sound: often the hoof regained normal shape.

In discussing these results on hoof ex­pansion one very important and often neglected point becomes clear: Con­traction is often secondary to the real problem. The contracted hoof has long been considered as a disease itself. As discussed, the shape was corrected by the best and most effective means at the time, to avoid problems associated with the contracted hoof shape. My view, stemming from this small sample, is that the lameness or problem thought to be caused by contraction was in fact the initial cause. A history was collected, hopefully to offer a clue to the problems. and it seems that it did. The acutely lame examples were often not bearing the horse’s weight for a length of time due to an abscess, fracture. or some other unknown cause. The limb with this problem had the contracted hoof.

This is interesting if you review Emery, Miller, and Van Hoosen’s theory on the structure and function of hoof: “During the second phase movement . . . the sole flaftens and lower portion of the hoof expands as a result of the force exerted on the digital cushion." In other words: No weight, no expansion!

Prior to Adams’ translation of Lungwitz book, Miles’ book horseshoeing (1856) commented the great advantage of bringing in heels and fitting the shoe close. sc horse does not cast his shoe. if the projects beyond the hoof at any and more particularly the heels, the cannot fit the hole made by the s and stiff clay will cling around the jection and pull the shoe off?

Horses #1 through #4 in grop B. were used to substantiate the results, which were acute lameness and long standing. (Note that these were to be shod for the fracture first: hoof cotraction followed.)

In these four horses the fractures were in the wing of the third phalanx and only one was horizontal across P-Ill. Lameness was immediate, and hoof shapes appeared normal before the fracture. Remember that when shoeing for this type of problem you try to immobilize the hoof capsule and prevent expansion of the fractured pieces. Data in group B showed a progressive narrowing in the heel area.

Summary
In summary, these methods of treating the contracted hoof differ from the common teaching of today.
  1. Understand the primary cause.
  2. Realize hoof contraction is a secondary problem.
  3. Treat it as a state of correction, not a condition: shape follows function.