When Did Shoes Become Bad?
Many newcomers to horses are not aware of the different approaches to hoof care. They may assume shoes are required as much as shelter and feeds. Some owners will claim their horses are sore without them, so therefore they are needed for activities outside of the paddock.
Equine Podiatry
A shoeless approach focuses on making horses hooves healthy enough to perform without shoes. But why are horses shod to begin with? Let’s explore if there are positives to shoeing, or if a healthy shod hoof is a contradiction of terms.
The Side Effects of Metal Shoes
If the hoof does not need a shoe, then why is it shod? If support is needed, is a metal shoe the best choice? A modern convenience for many horse owners — shoes allow more capability than the hoof is able without, so are technically a performance enhancer, or prosthetic. This sounds good, but understanding side-effects and what a shoe can do to the hoof is important in making a decision about whether they are appropriate.
Impeded Development
The skeletal structures in a horses hoof don’t stop growing until they are around six or seven. Applying a fixed shoe to a growing hoof can impede development. Similarly, in Chinese culture, the feet of a child used to be bandaged so they remain small.
Long-term, a shoe weakens the internal structures that should naturally be weight-bearing. Typically a horse that is sound shod, but lame barefoot, is seen as ‘needing’ shoes, instead of the more accurate scenario of having weak feet. Imagine breaking your arm, and having it in a cast for six weeks. Your muscles would naturally atrophy. If you were to remove the plaster, your solution to strengthen your muscles would not be to put the cast back on. The hoof needs correct stimulation, and without, may not be strong enough to support the horse above it.
Won’t My Horses Hooves Wear down Quicker Than They Grow?
A common misconceptions is that the hooves stop growing or wear away more quickly than they grow without shoes, but this is untrue. The development of any tissue in the body is directly related to the forces exerted on it. The more the foot is stimulated by exercise and different surfaces, the more it grows. Hard working horses may not need their feet trimmed as often.
Get a Grip!
Studs are commonly used to increase traction for stability in poor conditions. However these transfer torsion and shear forces higher up the leg, into joints, muscles, tendons and ligaments. The foot is meant to slip a little with every step, and preventing this mechanism can lead to greater muscoskeletal problems. The back of the hoof is naturally designed to grip terrain. The frog — a leathery, triangular wedge, bars that dig into the ground and collateral grooves which gather material, are a superior design that provide more grip than a metal shoe.
Disciplines including Eventing, Dressage, Racing and Endurance that typically involve studded shoes, are having great success with barefoot horses. More commonly, people are gaining a competitive edge from being unshod.
Reduced Proprioception
Proprioception is the sense of knowing the location of your appendages. If you were to close your eyes and hold your arm out to your side, without seeing it you would be aware of its location. Research shows that the horses hoof is like a sensory organ with different types of sensory receptors to register impact, temperature, vibration, and pain. Barefoot horses have increased proprioception due to the sensory receptors being properly engaged and not masked by a shoe. This may be why a shod horse trips or stumbles.
Increased Concussion
A metal plate on the underside of the foot increases concussion on hard surfaces. A shoe effectively lifts the hoof off the floor. Structures designed to be weight bearing and absorb concussion are no longer used. The sole, excepting the periphery, frogs and bars are no longer engaged, leading to weakening. Engagement of the frog transfers forces to the digital cushion and lateral cartilages. When not used for a long time, they weaken.
The ‘Barefoot Blacksmith’, Professor Robert M Bowker, found almost all of the navicular horses he dissected had poor digital cushion and lateral cartilage development. A metal rim fixed to a flexible object is going to cause a restriction of flexion. Whilst a shod hoof can still expand at the heels, there is greater expansion in unshod feet. A study confirmed that a barefoot horse was much better at reducing the effects of impact, and absorbing and dissipating more concussive forces than a shod foot.
Peripheral Loading
"There has never been a study showing that the hoof wall is the actual loading structure but this premise is accepted as dogma."
A shoe results in the majority of the horses weight suspended on the outside of the hoof. As other weight-bearing structures are lifted from the floor, the walls and laminae take the entire weight.
In 2013 Bowker wrote about how peripheral loading can cause osteoporosis of the pedal bone. In horses that use weight bearing structures correctly, collagen fibres from the the periosteum — the thin covering of the pedal bone, are flat against this surface. When a foot is peripherally loaded, the upward movement of the walls and downward movement of the pedal bone cause the collagen fibres to attempt to stablilise by changing orientation and digging into the pedal bone surface. They act like anchors and create holes in the bone surface, resulting in osteoporosis.
A shoe only fits for a week or two. After that, the hoof has grown and taken the shoe with it. Since the walls don’t wear, the whole hoof gets longer, often making the toe longer (increasing break-over) and the heel more under-run. This was identified in the 1800s by vet Bracy Clark, whose drawings of the changes in foot shape during a period of being shod may illustrate the consequences of (possibly poor) shoeing. Peripheral loading can occur in a barefoot horse is too — if the wall is left too long it acts like a natural shoe and lifts the weight bearing structures from ground contact.
Holy Bacteria! 🦠
Metal shoes are nailed on through the white line and hoof wall. Not only does this weaken the wall structure, but it allows an entry route for bacteria to get into the wall. The black discolouring you see around a nail hole is bacteria and fungus. If the nails are clenched too tightly, blood flow to the underlying laminae is restricted. Combined with other health issues such as white line disease, the shoe can come clean off, taking large chunks of hoof wall with it.
An Outdated Technology
Metal horse shoes are simply outdated. The basic concept has not changed in over a thousand years, despite advancements in understanding of hoof anatomy.
The industry seems to have recognised this, and in the last decade, plastic or rubber shoes have been developed. Many are glued on. Whilst this addresses concussion issues, they still peripherally load the foot and do not engage weight bearing structures in the same way as barefoot horses. Some horses hooves will require protection, better, modern concepts such as hoof boots can provide this. These are only applied when protection is needed and can be fitted with therapeutic pads to actively develop or rehabilitate weak weight bearing structures to encourage rather than inhibit development.
If Your Horse Needs Shoes, Ask Yourself, Why?
Making a shoe from a piece of straight metal bar to the shape of a horses hoof is a highly skilled craft. The principle of a shoe as a prosthetic naturally lead to situations where there may be a genuine need in the short-term and benefits outweigh the side-effects. However the majority of domestic horses need stronger hooves, not prosthetics.
Shoes are successful at masking low levels of inflammation from poor nutrition, and make an unsound hoof appear more capable than without the shoe. Both point to underlying problems that need to be addressed. A barefoot approach deals with problems such as as minor lameness, infections, and imbalances as soon as they appear and before they can escalate into bigger problems.
With thanks to Mark Bailey DEP MEPA(UK), Equine Podiatrist covering Dorset, of Inside Out Hoofcare for the original insights and research into this topic.
Comments