Many shod horses lead relatively sound and trouble free lives, but the problem with shoeing is the unacceptably high number of horses which are prematurely retired or euthanized due to chronic lameness; lameness caused or contributed to by shoes and unnatural living conditions. Whilst the shoe is applied for protection, it also impedes the normal functioning of the hoof.
THE NEGATIVE EFFECTS OF SHOES.
REDUCES CIRCULATION - Expansion of the hoof is restricted by the nails and clips, this limits hoof mechanism and therefore blood flow. Shoes cause peripheral loading; the horse is forced to bear his weight on the hoof wall only. Veterinary researcher Robert Bowker has shown that peripheral loading reduces blood flow within the foot. These are the reasons why shod hooves feel colder than bare hooves. Blood carries nutrients and oxygen for growth and repair. This is why shod hooves grow more slowly than bare hooves. Reduced circulation also causes reduced feeling in the hoof.
Above: Thermographic images of the hind feet (left picture) and fore feet (right picture) of the same horse taken with the same temperature setting. The temperature is shown by the colours - red/yellow is warmer and blue/green is colder. The difference here is that the hind feet are bare, and the fore feet are shod.
INCREASES CONCUSSION – The shoe cancels out approximately 75% of the hoofs ability to absorb concussion. Concussion then travels up the leg damaging tendons and joints. Compare the footage on the links below.
CAUSES CONTRACTION – The healthy hoof is a cone shape, wider at the ground surface, narrower at the coronary band (below left). As it grows longer it also gets wider at the bottom. Shoes fix the width to what it was when the shoe was applied; it cannot get wider, so the hoof can become a cylinder shape, the same width top and bottom (below right).
The heels become narrower, the soft structures in the back half of the foot become compressed and wither (below left). This leads to pain in the back half of the foot when it impacts on the ground.
Below left is a contracted foot, and for comparison, below right is a healthy foot.
GREATER INJURY RISK – To field mates and human handlers. Horses don’t often kick with the intention of hurting the recipient, their kicks are playful or intended as a warning. The shoe adds weight to the blow (like knuckle dusters do to a punch) resulting in unintentional damage.
UNBALANCES THE HOOF – When the horse is re-shod the farrier removes excess growth and balances the hoof. He then applies the shoe which adds weight and length. Immediately hoof balance is affected. As the hoof grows longer it also grows forward and out from under the horse, balance and bio-mechanics grow worse. By the time the farrier returns the hoof has been poorly balanced for weeks putting the horse at greater risk of injury.
There are also advantages to shoeing;
- It allows horses to work on any surface without conditioning the hoof or adjusting diet and lifestyle. This enables us to keep the horse on an unnatural diet and in unnatural living conditions, which can lead to other health problems.
- It allows the application of studs to give the horse greater than natural traction. This puts extra strain on the joints and risks injury.
- It allows us to change the horses action, to create a higher knee action, a longer stride, or to make the horse move straighter. This puts unnatural and damaging stresses on the limb.
Above: A Tennesse Walking Horse demonstrating the extreme of intentional gait alteration with shoes and wedges. Minor alterations are enough to affect long term soundness.
- It allows horses with the beginnings of lameness to continue working sound - until the lameness progresses to a more advanced stage, with more advanced damage and poorer prognosis for a return to soundness. This is because the shoe reduces blood circulation in the hoof, which reduces sensation and so has an analgesic (pain killing effect). However, it does not prevent degeneration or promote healing.
Despite the above if the horses diet, environment and lifestyle are correct it is likely to have relatively healthy feet with shoes. Shoes put unnatural stresses and strains on the hoof, a healthy hoof has a better chance of withstanding these stresses. Horses with weak sick hooves are the ones that have the most to gain from natural hoof care, but often never have the chance as it is assumed their feet would collapse completely without shoes.