Interference & Forging

Fig. 7
Brushing

A wound that is not healing, the result of constant interference (brushing)

Pic. 8 Injury to the coronet.

    Forging (fig 1, 2 and 3) is a common fault in horses working in fast tempo in any of the three gaits. It usually refers to a hind leg hitting (catching) the front leg of the same side. In the walk it is commonly referred to as over reaching, which in most cases involves the hind toe of the shoe striking the front toe of the shoe (fig. 3), hence you can hear it; rarely the horse grabs the heel part of the front shoe (fig. 1) in the walk. During forging, the wounds, which some call the "treads", are caused mainly to the lower part of the front leg by the over reaching hind leg. 

   "Speedicuts" are generally called wounds caused to the hind legs by the front legs (fig 4, 5 and 6).

     Brushing (fig 7) is often referring to interference of one foreleg or hind-leg striking the leg of the opposite side. An injury to the inside of the knee or hock caused by the inside toe of the opposite leg is by some called a "speedicut". This injury is rare in riding horses but common in the thoroughbred and trotting racing industry and also not unusual in polo ponies. 

   Cross-firing refers to the diagonal interference of the legs e.g. right hind with the left front, usually up high with the knee or hock, not uncommon by the trotters and sometimes seen in runners, usually due to unsoundness.

    To help to understand various causes I have separated the types of interference into two categories, the constant or frequent and the sporadic (isolated overstepping etc.).

    Frequent Interference

    The constant or frequent interference in a sound horse can be the result of faulty conformation (body, legs), or the tiring of the horse and improper shoeing. In the case of conformation faults a specialized shoeing must be implemented in dealing with the problem, as well as the use of various leg protective devices or bandages to protect the legs from further damage. Of course if the cause is in improper shoeing, then corrective shoeing is the only answer. However, the improper shoeing is often not the cause, though most cases of forging and interference are blamed on the farrier, while actually the leading cause of frequent forging and interference is an unsound horse.

Unsoundness

    Much of the constant (frequent) forging and interference is caused by unsoundness of the horse. The most common injury that causes forging, as well as the brushing of the hind legs, are sore (strained) stifles, which is also usually the initial strain-injury in riding horses. Since both stifles are usually afflicted in the same way, and horses thus do not display any obvious irregularity or lameness in the gait, this lameness usually goes unnoticed for a long time until secondary and more obvious lameness will appear.
    Some of the forging, or as some say “over reaching” or "treading", depicted in figure 3 comes often during walk. This is usually a sign of problems with the strained stifles in riding horses. Unfortunately most folk turn to the farrier to correct this problem, which of course is the result of ignorance to the pain of the animal and soon or later it will show again elsewhere as lameness with much more complications.
    The too long hoof, especially in the short-coupled horses, can cause this type of forging of course, but that should be obvious since this will show only when the horse is due for shoeing. In some cases this type of over reaching (fig 3) will appear during the walk immediately after shoeing and the next day it is no longer present. This is usually a combination; a sign of the so-called “lose stifle” (strained stifle joints-ligaments) and due to stretching of the hind legs (stifles) through the shoeing process, the ligaments get somewhat over extended (stretched). Since this appears usually right after the shoeing, the farrier is more likely blamed for the fault; hence he usually makes some adjustments (squaring the hind toe etc.). If the latter is the case we should reexamine and reevaluate our riding and training first, before we try to solve the problem in the adjustment of shoeing.

Sporadic Interference

    Often, the sporadic interference, forging, or better-said accidental overstepping, is caused either by abusive, poor riding or by improper handling of the horse on the ground by the handler. The other common cause is genuinely accidental, which usually happens during turnout on the field (pasture).

    The so-called off balance running is very common cause. This usually happens during turnout, when the particular horse has not been turned out on regular basis (hence we take the shoes off before doing so). For example a racehorse that has spent most of his time either under rider or in the stall, and not accustomed to run without the weight on his back because he literally forgot how to move free, will usually run very excited, which leads to an extreme over-reaching that results in just about all of the forms of forging depicted on this page. This also very often results in serious injuries to the lower leg (hoof, coronet pic. 8), often losing the shoe and sometime resulting even in the fall of the horse (fig 1).  
    The off balance and sporadic (accidental) forging can be often seen even on horses that are turned out on regular basis and are accustomed to it. In most cases it is caused by uneven ground, usually in the mud, when the horse steps into a deeper spot with his front leg, in which case the timing is delayed due to the leg being stuck for a split second. This often results in catching the shoe (fig.1) with the hind leg and usually ripping it of, which is commonly contributed to some kind of “mud sucking of the shoe”, which is of course ludicrous and incorrect perception of what has actually happened. Mud does not suck the shoes off, horses rip them off, and hence it is mostly the front shoe that the horse loses in the deep mud.

   This cause of sporadic, infrequent forging and interference can be eliminated by a proper management and handling of the horse, and the farrier’s work need not to be altered. However, since many folks in the country are ignorant to most of the facts mentioned above, and many farriers are tired coming back and putting the front shoe back on the horse, the farriers will often shoe such horses short, which has its own consequences that will be discussed separately. One should keep in mind, that any decent and wise trainer will not turn out his valuable performance horse (racehorse, dressage horse, jumper etc.), but that is another issue that will be also discussed separately.

Improper (poor) riding.

    Horses that are abused and jerked around while ridden will often catch themselves in the fashion of figure 1, 2 and even higher on the heels. Some horses will interfere often in the front, most commonly hitting their shins in the splint area, which is very common among the young reining horses today, usually during the spinning, mainly due to the incompetence of the rider.
   The jumping horse is often being jerked in-between the jumps or just plain stupid wild and off balance riding anywhere will do the damage. It is obvious that the riding has declined to such point that most of the riders do not feel comfortable riding their performance horses without having them wrapped up like an UPS package, which by the way often interferes with freedom of movement in the horse.

  Typical examples of various types of forging, brushing (speedicutting) or even diagonal “cross-firing” can be seen in the trotting industry, which is very demanding on the horse and on the precise positioning of the legs in such extremely high speed in trot. Only a slight unsoundness can result in major interference, as well as any small deviation in shoeing. The speedicutting in thoroughbred racing is exclusively a result of unsoundness.

    Of course a fault in shoeing can cause interference, but this cause is not as frequent as it’s usually perceived to be. Hence, before we start to make any adjustment to shoeing, it is best that we first reexamine the work that we do with the horse (riding, training etc.) as well as the soundness of the horse. The latter should be our primary concern in the prevention of further injuring the horse past the point of repair.
    Some of the injuries come slowly and those are usually the ones that become permanent. 90% injuries related to training and riding can be prevented, something to take to heart. Further discuss the issue with your farrier and if he does not see a fault in his work then there is more likely a soundness problem. Horses do not have to go visibly lame when sore or in pain.