Everything a horse does, it does on its feet. No matter how well bred or how good their conformation, if their feet are of poor quality or structure, then the rest of the animal is compromised to some degree.
Because of human intervention in horse breeding, the process of "natural selection" no longer applies. As a result, we are not necessarily breeding the structural strength into horse's feet needed to cope with the forces that racing and other sports place on them. There are surprisingly few horses of any breed with perfect feet, although fortunately there are very few with extremely dysfunctional feet. Breeding, domestication, neglect and poor shoeing are all factors that may contribute to less than ideal feet. Given that the horse spent sixty million years evolving to its present form (without shoes on), shoeing carried out to the very best of a farrier's knowledge and ability still has, to some degree, a negative effect on hoof function.
But with specialist knowledge the farrier can help compensate for some of the short-falls that occur as a result of domestication. The basic reason for shoeing is that the horse wears down its feet faster than they grow. Anatomical and physical knowledge of the horse's legs and feet, coupled with an understanding of how the horse moves (biomechanics), as well as forging, shoeing skills, and horse sense are all elements needed to be an effective farrier.
Regular balanced hoof trimming and shoeing are essential to help achieve maximum locomotive output. On average, a racehorse needs shoeing every four to five weeks. Correct shoeing may help avoid damage to tendons, ligaments and joint structures of the lower leg. The higher the performance demanded of the horse, the higher the demands on their legs and feet. Consider, if we can increase a horse's stride length by 10mm for the same energy output, then we gain one metre over one hundred strides – a significant gain when a nose can be the difference between winning or coming second.
Most thoroughbreds race in aluminium shoes called plates. These are light and strong, and wear remarkably well. While most are shod with aluminium plates, a few still use light steel plates. Initially, when a horse first comes into work, a medium-weight steel shoe is used as this will both wear and support the foot well. The switch is made to aluminium plates once the horse's preparation has reached the stage of either trialling or racing. Aluminium plates are a fairly recent product, having been introduced within the last 10 or so years. Previously, horses were raced in lightweight steel shoes and worked in work shoes. These were interchanged when the horse raced, usually on race day. This was an added expense and also more damaging to the feet due to the extra nailing involved. Today, once the horse is racing they stay in their plates until they are worn out. At this time the feet also need to be trimmed and rebalanced.
The New Zealand Farriers Association (NZFA) has developed rules for shoeing, enforced by New Zealand Thoroughbred Racing. Each horse is inspected before its race by a designated plate inspector. These rules are not necessarily related to best shoeing practice. Rather they pertain more to the safety of the horse and jockey, and fairness to the racing public. Unlike a trotter, there are few "interference" problems at the gallop. Interference is when a horse strikes another leg mid-stride. At the gallop the toe of the leading front leg can sometimes come in contact with the diagonal back leg, an interference called speed cutting. There are ways that the farrier can shoe a horse to help prevent this. This usually involves making a variation to the shoes and/or the angles of the feet. Another problem is when the hind fetlocks distend down so far at the support phase of the stride that they come in contact with the ground, causing inflammation and skin breakage in this area. Some of the causes of stride-related problems may not necessarily come from the horse's feet, but can be due to incorrect conformation, or from the horse compensating for soreness somewhere else. This may even be soreness in the mouth; hence equine dentistry is also important.
I have been shoeing professionally for 15 years, and shoe for two of the South Island's more successful thoroughbred stables. However, my work also involves shoeing a variety of horses, including standardbreds, show jumpers, eventers, hunters, endurance and polo ponies, clydesdales, and even the odd donkey.
As a result of technology there are many different types of machine-made shoes available. This has considerably reduced the time spent hand-forging my own shoes, although I still make some specialist shoes that cannot be bought. Lameness from the feet or legs are specialist areas that I often deal with in conjunction with the veterinarian, and for which such specialised shoes might be made.
There are many products on the market that we can use to enhance hooves. One of the most useful is Equibond. This is a two-part mix that sets to the same consistency as the hoof wall and enables us to add to or repair hoof – a fairly recent innovation and a great concept as in the past we have only been able to remove hoof.
One of my roles is as an assessor and tutor for the NZFA, which has developed NZQA-registered units and courses that make up the Certified Farrier certification. Of concern is a lack of trainees undertaking these courses, which may result in fewer skilled farriers throughout the industry. For the benefit of the horse we need to encourage more of our young, horse-orientated people into the profession.