Pathologies

Definition:

Bone Oedema like lesions represents a general term describing an area of abnormal signal intensity at MRI, indicating fluid within the bone. It is often referred to as a bone bruise/contusion. A bone contusion (bone bruise) is a relatively common injury to a bone that is less severe than a bone fracture, resulting in injury to the bone on a microscopic level, without a discreet or visible fracture line on x-ray or advanced imaging such as MRI or CT scan.

Cause:

Maladaptation of the bone from repetitive overload without adequate rest periods during training and competition, compounded by impaired shock absorption at impact is the main cause. Another common cause is an acute traumatic overload at impact from landing especially on a hard surface.

Effects of Twin Shoes: 

protective effect (reduced force) on the bone by maintaining natural shock absorption capacity of the hoof (including digital cushion and frog) by allowing a normal functioning hoof mechanism (heel movement), circulation and biomechanics to take place.

Definition:

Navicular disease is a chronic degenerative condition of the navicular bone that involves 1) focal loss of the medullary architecture (with subsequent synovial invagination), 2) medullary sclerosis combined with damage to the fibrocartilage on the flexor surface of the bone.

Cause:

Besides genetics, altered biomechanics leading to increased force on the navicular bone at mainly impact and push-off play a role in the development of navicular disease.

Effects of Twin Shoes: 

protective effect (reducing force) on the navicular bone by (1) maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility), by (2)   maintaining hoof angle between shoeing intervals due to more equal hoof wear of toe and heels, and by (3) light weight shoe design.

Definition:

Pedal osteitis is a radiographic finding of demineralization of the solar margin of the distal phalanx, commonly associated with widening of vascular channels near the solar margin, which is best observed on a 65° proximal-distal dorsopalmar radiographic view. Although the term is usually used to describe changes in the dorsal distal (toe) solar margin, it can be used to describe bone resorption of any aspect of the solar margin of the distal phalanx. The bony resorption usually occurs due to chronic or repeated pressure and/or inflammation of the affected region.

Cause:

chronic or repeated pressure and/or inflammation of the affected region or secondary to bone infection.

Effects of Twin Shoes: 

can potentially help by improving circulation in the foot and eliminating focal pressure (the Twin shoe does not bind the hoof capsule).

Definition:

A fracture is a partial or complete break in the bone. Maladaptation of the bone from repeated overload without adequate rest periods during training and competing, compounded by impaired shock absorption at impact is the main cause of fracture. Another less common cause is a traumatic accident (kick).

Cause:

Maladaptation of the bone from repetitive overload without adequate rest periods during training and competition, compounded by impaired shock absorption at impact is the main cause of fracture. Another less common cause is a traumatic accident (kick, fall, …).

Effects of Twin Shoes: 

protective effect (reduced force) on the bone by maintaining natural shock absorption capacity of the hoof (including digital cushion and frog) by allowing a normal functioning hoof mechanism (heel movement), circulation and biomechanics to take place.

Definition:

Synovitis and capsulitis are inflammations of the tissues that line the joint i.e. the synovial membrane and the joint capsule.

Cause:

(all joint diseases): repetitive or acute exercise-induced overload in combination with altered  biomechanics and impaired shock absorption leading to increased strain on the joints.

Effects of Twin Shoes: 

protective effect (reducing stress) on the joint and  surrounding structures by:

–   maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility),

​-   maintaining medio-lateral joint balance on circles and on uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility),

–   maintaining natural shock absorption capacity of the hoof by allowing a normal functioning hoof mechanism (heel movement) and circulation and

–   maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe & heels.

Definition:

Osteoarthritis is the degeneration of the joint cartilage and underlying bone but also effects the other joint structures (synovium, ligaments, …) causing inflammation, resulting in pain, stiffness and loss of mobility)

Cause:

(all joint diseases): repetitive or acute exercise-induced overload in combination with altered biomechanics and impaired shock absorption leading to increased strain on the joints.

Effects of Twin Shoes: 

protective effect (reducing stress) on the joint and  surrounding structures by:

–   maintaining normal distal limb joint angulation by allowing a normal functioning hoof  mechanism (heel movement and sagittal flexibility),

​-   maintaining medio-lateral joint balance on circles and on uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility),

–   maintaining natural shock absorption capacity of the hoof by allowing a normal functioning hoof mechanism (heel movement) and circulation and

–   maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe & heels.

Definition:

Articular cartilage is a complex tissue that lines the ends of the bones in the joint, providing a smooth surface for the bones to move against each other with a pain-free glide. When cartilage damage occurs it can be graded in severity from just showing softening and inflammation to full thickness cartilage loss and subchondral bone exposure.

Cause:

(all joint diseases): repetitive or acute exercise-induced overload in combination with altered biomechanics and impaired shock absorption leading to increased strain on the joints.

Effects of Twin Shoes: 

protective effect (reducing stress) on the joint and surrounding structures by:

–   maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility),

​-   maintaining medio-lateral joint balance on circles and on uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility),

–   maintaining natural shock absorption capacity of the hoof by allowing a normal functioning hoof mechanism (heel movement) and circulation and

–   maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe & heels.

Definition:

the subchondral bone is located deep to the articular cartilage and is highly responsive to loading. Subchondral bone disease is a term that describes the different phases and spectrum of pathologic changes observed within the subchondral bone when the bone does not have the opportunity to appropriately complete the repair processes that take place in response to repetitive loading through the normal adaptive process of bone modeling (geometric sculpting of bone by formation and/or resorption) and remodeling (damaged bone is resorbed by osteoclasts, followed by recruitment of osteoblasts to replace the removed bone).

Cause:

(all joint diseases): repetitive or acute exercise-induced overload in combination with altered biomechanics and impaired shock absorption leading to increased strain on the joints.

Effects of Twin Shoes: 

protective effect (reducing stress) on the joint and surrounding structures by:

–   maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility),

​-   maintaining medio-lateral joint balance on circles and on uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility),

–   maintaining natural shock absorption capacity of the hoof by allowing a normal functioning hoof mechanism (heel movement) and circulation and

–   maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe & heels.

Definition:

Desmitis is an inflammation of a ligament and results from micro-tears that happen when the ligament is acutely overloaded with a tensile force that is too heavy and/or too sudden.

Desmopathy is a degeneration of the ligament’s collagen in response to chronic overuse; when overuse is continued without giving the ligament time to heal and rest, such as with repetitive strain injury.

Enthesopathy refers to a disorder (problem) involving the attachment (insertion) of a tendon or ligament to a bone. This site of attachment is known as the enthesis.

Cause:

repetitive or acute exercise-induced overload further predisposed/accelerated by altered biomechanics leading to increased strain on the suspensory at mid-stance and push-off.

Effects of Twin Shoes: 

protective effect (reducing strain) on the suspensory apparatus by:

​-   maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility),

​-   maintaining medio-lateral joint balance in circles and on an uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility) and

​-  maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe and heels.

Definition:

Tendinitis is the inflammation of the tendon and results from micro-tears that happen when   the musculotendinous unit is acutely overloaded with a tensile force that is too heavy   and/or too sudden.

Tendinopathy/Tendinosis refers to a degeneration of the tendon’s collagen in response to chronic overuse; when overuse is continued without giving the tendon time to heal and rest, such as with repetitive strain injury.

Cause:

repetitive or acute exercise-induced overload further predisposed/accelerated by altered biomechanics leading to increased strain on the SDFT at impact and mid-stance.

Effects of Twin Shoes: 

protective effect (reducing strain) on the SDFT by:

​-   maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility),

​-   maintaining medio-lateral joint balance in circles and on an uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility) and

​-  maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe and heels.

Definition:

Tendinitis is the inflammation of the tendon and results from micro-tears that happen when   the musculotendinous unit is acutely overloaded with a tensile force that is too heavy   and/or too sudden.

Tendinopathy/Tendinosis refers to a degeneration of the tendon’s collagen in response to chronic overuse; when overuse is continued without giving the tendon time to heal and rest,  such as with repetitive strain injury.

Cause:

repetitive or acute overload further predisposed/accelerated by altered biomechanics leading to increased strain on the DDFT at push-off.

Effects of Twin Shoes: 

protective effect (reducing strain) on the DDFT by:

​-   maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility),

​-   maintaining medio-lateral joint balance in circles and on an uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility) and

​-  maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe and heels.

Definition:

Desmitis is an inflammation of a ligament and results from micro-tears that happen when the ligament is acutely overloaded with a tensile force that is too heavy and/or too sudden.

Desmopathy is a degeneration of the ligament’s collagen in response to chronic overuse; when overuse is continued without giving the ligament time to heal and rest, such as with repetitive strain injury.

Enthesopathy refers to a disorder (problem) involving the attachment (insertion) of a tendon or ligament to a bone. This site of attachment is known as the enthesis.

Cause:

repetitive or acute exercise-induced overload further predisposed/accelerated by altered biomechanics leading to increased strain on the collateral ligaments during turning and on uneven footing.

Effects of Twin Shoes: 

protective effect (reducing strain) on the collateral ligament by maintaining medio-lateral joint balance in circles and on an uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility).

Definition:

Degenerative suspensory ligament disease (DSLD) is a condition that affects the horse’s connective tissue. Connective tissue is tough tissue that connects, supports, binds, or separates other tissues or organs; examples include tendons and ligaments, but also the tough membrane that surrounds muscle cells. A key feature of DSLD is collagen disruption and the accumulation of substances called proteoglycans between the fibers. In fact, the name “DSLD” is a bit of a misnomer, since the condition doesn’t only affect the suspensory ligament. Since other structures besides the suspensory ligament can be involved with this condition, it has been proposed that the condition be called Equine Systemic Proteoglycan Accumulation (ESPA) as opposed to DSLD. The condition has been diagnosed in multiple breeds. Besides genetics, other possible causes are underlying metabolic disorders, hormonal imbalance and/or corticosteroid overuse.

Cause:

Besides genetics, other possible causes are underlying metabolic disorders, hormonal imbalance and/or corticosteroid overuse. altered biomechanics at impact and mid-stance can further lead to increased strain on the already compromised suspensory apparatus.

Effects of Twin Shoes: 

protective effect (reducing strain) on the suspensory by:

​-  maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility)

​-  maintaining medio-lateral joint balance in circles and on an uneven surface by allowing a normal functioning hoof mechanism (lateral flexibility) and

–  maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe & heels.

Definition:

Low underrun heels have a Heel Angle which is 5° lower than the Dorsal Hoof Wall Angle (DHWA) and with the structure of the heels being compromised.

Cause:

Genetics, trimming and shoeing, abnormal load on the caudal part of the hoof, conformation, posture, tendon (flexural) laxity, leg limb asymmetry.

Effects of Twin Shoes:

As the Twin shoe moves with the hoof instead of the hoof moving over the shoe (which is the case with a one-piece shoe), there is minimal and a more even wear pattern from heel to toe on the support surface of the shoe which in turn keeps the coffin bone angle and hoof wall angle more consistent during the shoeing-interval. As a farrier you are not fighting the fact that you have to trim toe and no heel because the heels are worn down through friction with the shoe.

Definition:

Cause:

Genetics, conformation, posture, gait (loading) pattern, pain (in the limb or foot), trimming and shoeing, thrush, tendon (flexural) contraction, leg limb asymmetry.

Effects of Twin Shoes:

By freeing up the toe we allow normal unrestricted heel movement like in barefoot, whereas a one-piece shoe limits heel movement up to 40-50%. This allows the heel bulbs and coronet band to relax and the heels to open up.

By allowing heel movement and using a thinner shoe (7 mm) we start activating and engaging the frog, creating a healther frog ratio (width/length ratio)

Definition:

a hoof capsule distortion that results from displacement of one heel bulb proximally relative to the adjacent heel bulb. Disparity between the medial and lateral heel length of 0.5 cm or more.

Cause:

medial or lateral overload or unequal load (focal pressure) of the hoof capsule due to conformation, posture, gait (loading) pattern, trimming and shoeing.

Effects of Twin Shoes:

The two branches of the Twin shoe can move independently and as such the Twin Shoe does not bind the hoof capsule (fixate a 3-dimensional structure in  a 1-dimensional plane like a one-piece steel shoe does). The freedom the Twin Shoe gives to the hoof capsule allows the coronet band to settle down,   distribute the load over the hoof more symmetrical (especially during movement) and as such help resolve or prevent sheared heels and quarter cracks.

Definition:

A quarter crack is a hoof wall defect at the quarter. A true quarter crack originates at the coronet band and extends through the full thickness of the hoof wall into the dermis, leading to instability, inflammation, and/or infection.

Cause:

It generally occurs from excessive pressure (unequal load toe to heel) on the toe area due to conformation (club foot), genetics (large crena), posture (standing with leg back (in retraction), gait pattern (toe landing), trimming and shoeing (long toe, long hoof wall, excessive medial/lateral flares, weakening of the dorsal hoof wall due to overdressing (rasping) it, mechanical lever arm at the toe)

Effects of Twin Shoes:

The two branches of the Twin shoe can move independently and as such the Twin Shoe does not bind the hoof capsule (fixate a 3-dimensional structure in a 1-dimensional plane like a one-piece steel shoe does). The freedom the Twin Shoe gives to the hoof capsule allows the coronet band to settle down, distribute the load over the hoof more symmetrical (especially during movement) and as such help resolve or prevent sheared heels and quartercracks.

Definition:

A toe crack is a vertical hoof wall defect in the dorsal hoof wall. A toe crack generally originates at the ground surface (bottom) and migrates upwards in a vertical direction. They are generally superficial (partial hoof wall thickness), but can be full thickness. they are generally benign but can sometimes lead to instability or infection (white line disease).

Cause:

Conformation (upright/club foot with dorsal flare/dish). Long toe/flared hoof wall (excessive growth or long shoeing cycles), trimming and shoeing (over dressing the dorsal hoof wall, or not addressing the toe/quarter flare (long toe pillars)), prominent crena or seedy toe, shoe loss, stress point at toe clip, poor hoof wall quality (nutrition, genetics, …).

Effects of Twin Shoes:

The Twin Shoe can be used as a one-piece shoe where the double toe clip stabilizes the toe crack on each side. However, for resolution of toe cracks in general it’s all about proper trimming, nutrition and treatment of seedy toe if present.

Definition:

Flares are a type of hoof-capsule distortion where the wall horn is being stretched outward and pulled away from the coffin bone. The wall of a healthy hoof should follow the same angle all the way from the coronet band to the ground. Flares are present when part of the wall deviates or “dishes” outward from that angle. They can be observed by looking at the walls from the front (in case of medial or lateral flares) or side (in case of toe flares), and by viewing the foot from the bottom (stretched white line). The can be defined/measured more objectively as a hoof wall deviation of  0.30 cm.

Cause:

Similar to many hoof capsule distortions it is related to unduly stressed portion of the hoof wall due to abnormal distribution of forces (Increased load or weight-bearing by a portion of the wall), other common causes are diet/metabolic status, growth/wear imbalance exacerbated by long shoeing intervals and wet environment.

Effects of Twin Shoes:

As with any other hoof capsule distortion, besides from the hoof wall being too long or weak, flares are often a consequence of the hoof being bound in one   plane. So, the hoof capsule fights the way it is bound by the shoe leading to a hoof capsule distortion. As the two branches of the Twin shoe can move   independently, the Twin shoe does not bind the hoof capsule (fixate a 3- dimensional structure in a 1-dimensional plane like a one-piece steel shoe does). The freedom the Twin shoe gives to the hoof capsule allows the hoof   capsule to be where it wants to be, distribute the load over the hoof more   symmetrical (especially during movement) and strengthen the hoof capsule through exercise, creating a stronger hoof wall with less flares.

Definition:

Cause:

Genetics, nutrition, environment, aging, metabolic status, past pathologies, trimming and shoeing.

Effects of Twin Shoes:

By improving circulation and mechanical stimulation by allowing the natural hoof mechanism to function increased growth rate is seen with Twin Shoes allowing for thicker sole production. Over time a stronger and healther sole/wall connection is formed which helps to improve the arch strength.

Definition:

Thin/brittle hoof walls are not a stand-alone hoof Health issue. It is often associated with thin/flat soles and compromised sole/hoof wall connection (White line/laminae). It is expressed as weak, flaky hoof wall that cracks easy. These horses have a hard time holding a shoe.

Cause:

Genetics, metabolic health status, diet, environment, mechanical leverage/pressure, trimming and shoeing, hoof wall injury or trauma all leading to poor hoof quality.

Effects of Twin Shoes:

Obviously the most important thing to address brittle hoofs is to eliminate the root cause itself. However, Twin Shoes can help by improving circulation and mechanical stimulation. This in combination with exercise will lead to increased growth rate and stronger/thicker hoof walls over time. Note, that in these cases micro-management of hoof care will be key to be successful.

Definition:

Laminitis is damage and inflammation of the tissue between the hoof and the underlying coffin bone (distal phalanx, P3). This tissue, the laminae (also called lamellae), is actually folded layers of tissue, contacting the surface of the bone on one side and the inside of the hoof wall on the other, connecting the two. Depending on how severely these attachments are weakened, the outcome can range from mild foot soreness to separation of the coffin bone and hoof (founder). The front hooves, which bear the majority of the horse’s weight, are most commonly affected, but it can also occur in the hind hooves.​

Cause:

Laminitis can be the outcome of excessive grain intake, access to pasture high in sugars, compensatory weight bearing due to injury of the opposite limb (supporting-limb laminitis, or contralateral limb laminitis), ingestion of toxic plants (such as black walnut shavings), and excessive work on hard surfaces (road founder). Laminitis often occurs due to diseases such as equine metabolic syndrome (EMS) or pituitary pars intermedia dysfunction (PPID, aka Cushing’s Disease) (endocrinopathic laminitis), sepsis or systemic inflammatory response syndrome (SIRS) (sepsis-related laminitis).

Effects of Twin Shoes:

Have no direct place in laminitis cases especially acute laminitis where stabilization and unloading the hoof wall/laminae is key. It may have a place in the more chronic case to help restore circulation but more research need to be done before recommending Twin Shoes in laminitic cases.

Definition:

Nail bind is the term used when the nail of the horse’s shoe is placed too close to the sensitive laminae of the foot, resulting in pressure on the lamellae within the hoof capsule. Shoe tightness occurs in some horses when shoeing a horse with a traditional one-piece shoe, locking the hoof capsule in a neutral (semi-contracted) state, restricting its movement with a feeling like you are wearing one size to small of a shoe.

Cause:

Shoeing a a horse with a one-piece shoe, the shoe is basically too small as soon as the horse puts the foot on the ground. The hoof is shod in a lifted thus contracted position but on the ground (under load) the hoof expands. This feeling of too tight of a shoe/nail leads in some horses to short/choppy gait.

Effects of Twin Shoes:

Definition:

Navicular syndrome is a chronic and often progressive disease affecting the navicular bone and bursa, deep digital flexor tendon (DDFT), and associated soft tissue structures composing the navicular apparatus.

Note: Navicular syndrome, navicular disease, and caudal heel pain are all referencing the same condition. Veterinarians have moved away from calling it navicular disease because disease means there is one problem, where syndrome means there are multiple or varying problems. We now know that this condition has many components and it varies from horse to horse, so navicular syndrome is a more accurate description of what we are treating. It is often referenced as caudal heel pain as well to describe the location of the lameness; “caudal” meaning the back of the foot, and “heel pain” because that is the generalized area of the lameness.

Cause:

Repetitive or acute overload further predisposed/accelerated by altered biomechanics leading to increased strain on the caudal heel structures.

Effects of Twin Shoes:

protective effect (reducing strain) on the DDFT by:

– ​maintaining normal distal limb joint angulation by allowing a normal functioning hoof mechanism (heel movement and sagittal flexibility),

– ​maintaining medio-lateral joint balance in circles and on an uneven surface by allowing a normal functioning hoofmechanism (lateral flexibility) and

​- maintaining hoof angle between shoeing cycles due to more equal hoof wear of toe and heels.

– Proper development of the caudal hoof structures by allowing heel movement to take place as such protecting and reducing the stress in the underlying DDFT and navicular area.

Definition:

this term/classification refers to these horses that have multiple musculoskeletal health issues whether in one limb, different limbs or limbs and axial skeleton at the same time. This is not uncommon to see as horses are pray animals and masters in hiding pain/discomfort leading to compensatory overload injuries, where primary issues lead to secondary issues and so forth.

Effects of Twin Shoes:

Twin shoes can be an excellent choice in these cases as they allow natural biomechanics to take place minimizing stress on different structures during different parts of the stride as well as having a similar effect as pushing the reset button