Shoeing for Performance
 

They found that the distance they could travel was limited because the horses got sore footed. The Viking smiths found that they could make shoes from strips of iron, a very precious metal at the time, fashion nails and nail the shoes on. The technique worked so well that the Vikings were able to move their armies across Europe conquering all in their path. Eventually they were able to make their way to what is known today as Italy and help to collapse the Roman Empire.

After the Vikings withdrew the rest of Europe fell into feudalism and began the period of time known as the "Dark Ages". From the beginnings of the "modern horseshoeing" technique, little has changed except perhaps a greater understanding of the horse and the process. The Vikings utilized the most basic reason for the application of shoes, protection of the hoof from excessive wear. This is the most basic performance-enhancing feature of the horseshoe. In addition to protection we recognize four other categories of shoeing:

• Traction for enhanced performance
   
• Corrective for conformational faults
   
• Compensatory shoeing for gait faults
   
• Therapeutic for the treatment of disease or injury

Horseshoe Materials
Steel is by far the most common shoe material for many good reasons. It is strong and inexpensive and can be formed into a variety of shapes. It does have some drawbacks because of the hardness that can create lameness.

 Aluminum is an excellent shoe material. It is relatively inexpensive and can be forged in the same manner as steel. The softness of the aluminum is beneficial because the shoe more readily conforms to the horse’s way of going and the light weight is less fatiguing for a performance horse. A shoe made of aluminum is a fraction of the weight of a steel shoe with the same dimensions. A drawback to the aluminum shoe is they wear quickly in highly abrasive footings.

 Plastic shoes have some superior properties for absorbing concussion and some have excellent wear properties. However I find that the all plastic shoe has some shortcomings that keep it from being as useful as a metal shoe. Attachment is difficult because nails are prone to drive through the shoe and shatter the wall during the shoeing period. Some can be bonded to the hoof eliminating the nails however bonding is difficult and expensive.

Composite shoes are outstanding in certain areas of performance enhancement. Traction on pavement is best when a shoe with a urethane tread is used and concussion absorption is superior to any pad nailed between the shoe and the hoof. The main drawbacks for the composite shoes are the cost, which can be many times the cost of standard shoe and pad combinations.

  Traction
Traction is improved by shoes over the bare foot by the addition of shoes that:

• Have caulks, cleats or grabs that penetrate the ground or turf to improve the grip.
   
• Creasing or grooving the bar stock of the shoe itself increases traction.
   
• Have "Borium" or tungsten carbide applied to the ground surface.  Borium is harder than rocks or pavement and digs in to prevent slipping.
   
• Have a ground surface that is soft to afford a good purchase on hard surface. Many compounds such as rubber, polyurethanes and plastics are used.

 Correction
The correction aspect of horseshoeing is when the application of the shoe affects a permanent change in the horse's conformation. This is only possible when the horse is still growing. Differential loading of the physeal growth plates causes a permanent change in the conformation of the leg. Mature horses with fused physes are not able to have angular or rotational deviations changed with shoes.

Compensatory
All other corrective shoeing measures applied after the animal is mature are what I call compensatory. Poor conformation is the primary cause for interference of the limbs when the horse is doing its job. Shoes are constructed with different features designed to correct the foot flight so the limbs do not collide. Configuring the shoe to provide more support or to modify the breakover can help deficient conformation.

Therapeutic
Injury and disease can cut short a performance horse's career. The use of the shoe may help to counter those effects and prolong the use of the horse. Increasing the coverage of the foot and decreasing concussion helps slow cartilage and bone degeneration. The support feature of a bar shoe helps prevent tendon and ligament strains. Increasing the web of the shoe or the addition of pads can help with sore feet by increasing the coverage of the sole. Concussion can be reduced by the use of pads or special shoes with treads.

Conclusion
Shoes sometimes are necessary for the optimum performance of our equine athletes. They can, in the quest for the blue ribbon or to be first over the finish line, create a dangerous condition for the horse. For example, increased strain on bones and joints caused by increased traction is going to show up as injuries over the long term. However, shoes have undoubtedly helped countless horses to cope with the job they are required to do with comfort and safety when chosen and applied correctly

The Trouble with Tradition
 

 Formaldehyde, concentrated solutions of Iodine, turpentine and used motor oil have been used on the hoof. There are many reasons not to use these compounds because they are toxic, even less reason when there are far better treatments available today. 

 Trimming the hoof to fit the shoe has always been viewed as improper shoeing technique, however there are many farriers and owners who advocate "backing the toe up" for horses that they perceive to have a long toe. Shaping the hoof to this pattern is the same as shaping it to a shoe. The result is a weakened hoof and related shoeing problems.

Race track shoeing creates problems by cultivating a hoof shape in the opposite direction. The notion is that a longer toe helps to win races by increasing the length of stride and increasing traction. Studies have shown that the long toe does nothing for speed but does greatly increase the chance of injury. The construction of the shoe also creates a poor hoof capsule because fine nails and lack of shoe support cause the farrier to adopt practices that are harmful to the hoof.

Traditional trimming theory is based on the assessment of the hoof and pastern alignment as the criteria for anterior/posterior balance. This requires that the heels of the hoof are sometimes left very long in order to accommodate this alignment. The excessive heel length has been shown to create soft tissue injuries. A new criterion for proper anterior/posterior balance of the hoof is to use the solar plane of the coffin bone. This requires different criteria for trimming the hoof and sometimes radiographs to be able to accurately find this anatomical reference.
 
  There are other times when tradition is still the most practical way of doing things. To break with tradition requires reasoning not rationalization. Question authority and require that the accepted ideas and techniques withstand scrutiny and challenges from new information.

Nutrition
The hoof capsule is a hornified cornified epithelium with a requirement for sulfur bearing amino acids. Good quality feeds are necessary for good strength and growth rate. Lysine, cystine and methionine are the critical amino acids for the strengthening disulfide bonds in the keratinized cells. These amino acids are found in good quantity in feeds based on milk or soybean protein. Gelatin is not rich in these amino acids and probably only plays a role in the sparing of the essential amino acids in the diet. Biotin is only a cofactor vitamin that assembles the amino acids. Diets low in the essential amino acids will show a very poor response to biotin supplementation. Trace minerals and micronutrients are also a vitally important factor in the health of the hoof. Supplementation of these is important in that most of the diets of our domestic animals are produced in a region that is not likely to have the variety of sources of these nutrients. Kelp has been shown to be a very effective supplement to provide these micronutrients. Probiotics are also very effective in promoting good hoof growth. They act on the gut flora to enhance digestion and absorption of the nutrients in the feed making more efficient use of the nutrients. Also the microflora produce biotin which is a natural source for this vitamin.
 
 Environment
Horses that are stall bound suffer the most insults to the hoof capsule. The environment the hoof is in is quite different than what is encountered just a few inches up. The bedding is s source of harmful ammonia, which attacks the hoof and destroys the quality of the protein in the hoof by breaking down the bonds in the keratinized protein. The hoof, from the feces and urine in the bedding absorbs excessive moisture. Fungus and bacteria thrive in the bedding and attack the hoof. 

 It has been my experience that the incidence of fungus infections in the wall is much lower in pasture horses than stall bound horses.  Excessively wet conditions are damaging to the hoof. The keratinized protein has a soluble phospholipid "glue" that is leached out. The cells swell with the osmotic pressure of the water and break the intercellular bonds. These bonds cannot be reformed, as the cells are no longer alive and capable of repair.

Many problems have been associated with excessively dry conditions such as cracks and contracted feet. It is my experience that aside from extremely difficult trimming and bruising from concussion on the hard ground there are no great ill effects from a foot that is dry. The hardness of the foot is necessary to withstand the conditions of the hard ground. It is not unlike calluses on our hands in response to hard work. Contraction of the hoof is a symptom related to a problem in the hoof or leg. Atrophy occurs when hoof is not fully loaded. Without proper stimulation the hoof contracts as a result of the change in weight bearing. There are normal variations of the hoof size throughout the year due to the content of water in the hoof. Wetter seasons are going to cause the hoof to swell and could possibly require a larger shoe. This is not necessarily a problem if the hoof remains reasonably healthy in the other respects.

Poor Shoeing Techniques
The largest problem with foot care is the removal of the wall unnecessarily. The reasons for this practice are numerous and most of the time is damaging to the hoof. Improving the appearance, "backing the toe up" or compensating for the lack of skill in fitting the shoe to the hoof are a few of the reasons the wall is removed. I am not advocating the wall should never be rasped on the outside but it should be undertaken with the greatest care and consideration of what is the benefit to the animal. Shoe design is another factor in the removal of the wall. Nail placement in the shoe sometimes makes it impossible to place the shoe securely and have a cosmetically good-looking job without removing the wall back to the shoe.

Poor Shoe Design
Horseshoe design greatly affects the hoof. The primary factors negatively impacting the hoof are the nail set in the shoe and the width of the web. If the nails are punched too fine, a common problem of racing and training plates, leads to all sorts of problems. To present a neat job the wall is rasped back to the shoe, ultimately removing enough wall to weaken the hoof. The narrow web shoe doesn't provide enough coverage of the sole to prevent pathologies from bruising and concussion. They are widely used because they are relatively easy to shape cold.

Owner Related Problems
Owners can and do create their own problems by trying to fix something that isn’t broken. This is primarily related to the excessive use of greasy hoof conditioners. In the desire to do the right thing the hoof becomes so saturated with softeners that the wall can no longer function. Splitting and peeling is misinterpreted as dryness and more conditioner is applied until the shoes no longer stay on and the foot is peeling because the wall is saturated with greasy softeners. The only remedy for this is to stop the hoof preparations and grow out a new hoof. There are no fat secreting glands in the hoof and it is not a normal constituent of the wall. Flexibility of the hoof is restored by moisture, and care must be taken not to over saturate the hoof so it is unable to cope with a tough environment. Topical preparations that are sealants may be detrimental because they block transpiration of moisture and exclude oxygen, which creates an environment favorable to anaerobic organisms to attack the wall. There are products that don’t block the normal "breathing" of the wall, protect from the harmful effects of ammonia and condition the keratinized protein to be more resilient without the use of grease. These have been shown to be beneficial in retaining the health of the hoof.