Rehab for Hoof Trauma with Andrew Bowe

This article is from the July 2020 Horse Deals magazine.

Rehab for Hoof Trauma with Andrew Bowe, Master Farrier and Equine Podiotherapist

From the day that foals hit the ground running, their hooves are subject to the constant trauma of hard hooves on hard ground. Such is life for a high mileage prairie animal.

Fortunately, evolution designed a hoof that is architecturally robust with the capacity to heal and regenerate from all of life’s little traumas. Left to themselves, horses do just fine.

But we have introduced unnatural stresses by adding the weight of rider and saddle and from accidental contact with man-made objects such as fences; along with the weakening of hooves by centuries of breeding for fast and pretty and an affluent domestic lifestyle and trouble is never far away for equine hooves.

Hoof injuries (traumatic breakage of the hard outer shell) can involve cracks, separation, tearing and even the occasional lost hoof capsule.

It’s a good thing that hooves have an incredible ability to heal and nowadays we have more treatment options than ever before to assist us. Alongside traditional metal shoes (to which we can add extra clips and bars), we now have many types of flexible plastic shoes, removable therapy boots, rehab pads, glues, screws, patches and casting wraps. And a greater knowledge of the physiological processes that drive hoof regeneration.

When faced with broken hooves we should aim high — not just applying a perpetual crutch — but full restoration.Deciding the best course of action in each case requires an understanding of the hoof’s anatomical structures, how they develop and how they interact in response to trauma.

Outwardly, equine hooves are a simple epidermal structure; a capsule of hardened skin that encloses and protects delicate internal structures.

Invisible from the outside, however, the hoof wall actually consists of two distinct halves; an outer wall and an inner wall which are tightly veneered together. Peering inside the hoof through a cadaver cross-section, the two components are easily discernible because the inner wall is non-pigmented (ie: bright white). With a keen eye it can actually be seen from the ground surface of a clean hoof where it is visible as a white ring inside the darker coloured outer wall.

The outer wall is a quite rigid structure, that grows in an orderly fashion downward from the coronet band and consists of parallel strands of keratin that are neatly packed and bonded together. It is the armour plating and protects internal anatomy from blunt force trauma, but it has no cross-thatching and is therefore susceptible to tearing and shearing forces along the orderly grain of keratin fibres. Just like a block of firewood with a straight grain is easily split.

The hoof needs reinforcement and this comes from the inner wall which is fundamentally different and is a plastic matrix that grows outwards like a second skin from the dermal tissue (which is commonly known as the corium) and it has no regimental structure whatsoever. It is viscous and has the ability to flow to where it is most needed for structural support.

The corium is itself an amorphous mass of vascular tissue which delivers blood (and therefore nutrients) to the cells that produce the inner wall. Healthy corium equals fast growth rate.

The inner wall, which cements to the outer wall, provides a malleable and durable interface between the hard outer shell and the fleshy corium. The most resilient hooves have the thickest inner wall which is synonymous with a fully functioning corium.

In times of trauma, the inner wall becomes the glue that holds a hoof together. This is why recovery from all manner of hoof injuries is optimised by stimulating production of the inner wall.

Inner wall growth is stimulated by maintaining hoof capsule flexibility and also by tasking it with weightbearing by removing the outer wall from that role.

A counterintuitive change of thinking

Most of the time, less is more.

Instead of routinely reaching for the usual (and logical) rigid shoe, totally engaging the outer wall and then adding more rigid material such as bars, clips, solid sole packing, glues, screws, wire and metal patches to further brace it as the case ‘requires,’ a broken hoof often recovers more thoroughly with controlled flexibility. Each case should be considered individually.

A hoof is always healthiest when barefoot, but when facing serious structural disruption, extra support is often needed for the remnant hoof capsule, at least initially.

An effective treatment plan to maximise recovery graduates from total rigidity back towards flexibility.

When a hoof suffering major trauma needs the stabilising protection of a rigid shoe (often with bars and clips) this can be applied during the immediacy of the emergency.

Afterwards, at the right stage of recovery, the rigid shoe may be swapped for flexible support such as a poly shoe.

The final phase of treatment then is barefoot rehab, with the hoof trimmed often enough with a rolled pattern to keep the hoof capsule tight and weight bearing stresses away from the outer wall and directed instead onto the inner wall to stimulate it. Happy hoof.

When a broken hoof is kept rigidly shod for the long term as the only component of the treatment plan, the growing hoof has a diminishing proportion of inner wall. Whilst there may be the appearance of external recovery, it is likely that such a hoof is an increasingly delicate house of cards that needs perpetual propping up.

It really is all about the inner wall.

Desi’s Hoof

A major resection for pedal bone infection

This hoof had a large area of the pedal bone surface necrotically infected (possibly due to blunt force trauma), so treatment required a large resection of hoof wall (by the farrier) followed by curettage of infected dermis and pedal bone (by the vet).

There was nothing left on the resected part of the hoof other than exposed bone, but the corium responded very quickly and came flowing back from all directions to ‘colonise’ the raw bone, followed closely by the inner wall also coming from all directions. As the outer wall grew down from above, it was able to ‘glue’ to the inner wall.

Due to the size and laterality of this resection, the hoof initially needed the support of a rigid bar shoe.

After a couple of shoeing cycles, there was enough structure for lateral balance, so the shoe was removed and a barefoot rehab regime with maintenance trimming begun in order to stimulate the inner wall for maximum speed and quality of regrowth.

Desi’s hoof quickly grew back as a complete unit with no evidence remaining of such a major operation.

Joey’s Hoof

A major breakage complicated by seedy toe infection

This over-long hoof was torn apart in a rough paddock and became infected with seedy toe. He was a big horse and quite lame, so he needed a shoe for comfort, but in this case, the aim was to maximise the growth of inner wall to cover the exposed corium and protect it from further bacterial invasion. For this reason, a fully flexible polyurethane shoe was applied from the beginning.

Glue was used (but sparingly, due to the rigidity of cured glue inhibiting hoof flexibility if used to excess) and the attachment was supported by numerous self-tapping screws.

The diseased tissue was vigorously treated at the beginning with peroxide and then with a more benign topical agent (potassium permanganate, commonly called Condy’s Crystals) to allow healthy hoof growth whilst still preventing bacterial activity.

The flexible shoe stimulated the hoof such that it was only needed once and the remainder of the recovery was barefoot.

Joey soon had a strong and well-connected hoof capsule and returned to his original level of soundness.

A closing note of caution when dealing with hoof trauma: Your hoofcare professional should be the first port of call for hoof trauma cases, but if there is ongoing lameness or infection, it is always best to seek veterinary assistance.

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