Clubfoot is a congenital or acquired distal interphalangeal flexural deformity of the toe. In general, a clubfoot can be defined as a hoof that meets the ground at an angle greater than 60 degrees.

This limb deformity occurs with an upright or straight tubular appearance of the foot combined with narrow and contracted heels, giving a “club-like” look. The degree of clubfoot and the clinical presentation can range from a mildly upright and a small hoof with a dorsal hoof wall angulation more than 60 degrees to a toe that is buckled forward with an angle greater than 90 degrees at the distal interphalangeal joint (coffin joint). In severe cases, destruction of the dorsal hoof wall, sole pressure, hemorrhages and pedal osteitis occur.

This limb deformity has been classified into two stages. In stage one, the hoof axis is less than or equal to 90 degrees. In stage two, the angle of the dorsal hoof wall to the ground is greater than 90 degrees. Other classifications are divided into four grades.

• Grade 1. A clubfoot that has a hoof axis of 3 to 5 degrees greater than the contralateral foot, fullness at the coronary band and an aligned hoof-pastern axis.
• Grade 2. A clubfoot that has a hoof axis of 5 to 8 degrees greater than the contralateral foot, a steep and slightly broken forward hoof-pastern axis, growth rings that are wider at the heel than at the toe and the heel does not touch the ground after trimming.
• Grade 3. A clubfoot that has a broken-forward hoof-pastern axis, mild concavity in the dorsal hoof wall, growth rings that are twice as wide at the heels as those at the toe and demineralization and lipping along the apex of the distal phalanx.
• Grade 4. A clubfoot that has a hoof angle of greater than or equal to 80 degrees, a severely broken-forward hoof-pastern axis, markedly concave dorsal hoof wall, the height of the coronary band at the heels is equal to that at the toe, extensive demineralization and rotation of the distal phalanx.

Clubfoot Etiology

In most cases, this limb deformity develops because of a shortening of the musculotendinous unit of the deep digital flexor tendon (DDFT) relative to the bony column, which results in hyperflexion of the distal interphalangeal joint. In single cases, which are mainly congenital, a laxity of the digital extensor tendons can be causal for a flexural instability of the distal limb and a buckled forward toe.

The etiology for this deformity is generally undetermined. However, some factors for developing a congenital or acquired clubfoot has been described.

• Congenital clubfoot. Factors that encourage a congenital clubfoot include genetics, intrauterine malposition, teratogens and influenza virus exposure.
• Acquired clubfoot. Factors encouraging an acquired clubfoot include genetics, fast skeletal growth, nutrition, keeping (e.g., abrasive, firm grounds), body conformation (e.g., long legs, small heads), lateralized grazing posture (i.e., a preferred supporting leg), pain and lameness.

Managing a Clubfoot

In general, the orthopedic treatment of the limb deformity is less successful without adaption of management and additional measures. The specific treatment protocol and long-term management may vary depending on the age of onset, underlying etiology, severity, duration, secondary complications and client expectation. Still, there are some general measures that aid a beneficial outcome of the therapy.

Manual therapy or osteopathy can be used to decrease the tonus of the triceps muscle and other contracted muscular units in combination with gentle stretching of the legs reduce tension and contraction of the soft tissue, decrease muscular pain and increase well-being of the patient. Massages of the contracted triceps and carpal flexors is appreciated by the foals. However, aggressive physical manipulation and overstretching of the limb should be avoided to prevent fatiguing the muscular section of the musculotendinous unit.

In this context, it is advisable to reduce physical exercise and locomotion of the foal to decrease stress and strain on the soft tissues causing an increase of fatigue in combination with the subsequently described orthopedic treatments. It is useful to keep the foal in small paddocks to reduce locomotion for the time of orthopedic manipulations. Jumping around, playing with other foals or running behind an active mare are definitely contraindicated. In severe cases with lameness and muscle fatigue, stall rest is necessary until relaxation of the musculotendinous unit is present and the deformity is improved. This can last up to 2 weeks. If lameness is present, it is advisable to apply painkillers to reduce pain induced contractions and relief posture.

In cases where orthopedic treatments with dorsal extension were performed, the foals need to be kept with less bedding material to promote the effect of the orthopedic treatment. Still, cleaning the stall is crucial to maintain a dry and hygienic environment to prevent rotting of the frog and destruction of hoof horn.

In severe cases or if the orthopedic treatment itself was not successful, administration of oxytetracycline (44 mg/kg IV, SID) can also facilitate improvement of the deformity. In extreme situations, surgical resection of the accessory ligament of the DDFT becomes necessary to prevent long-term overload of the tendon, the navicular region and the distal phalanx.

In general, it is important to emphasize that the orthopedic treatment of clubfeet in foals without an appropriate management and care is not just inefficient, but even harmful for the patient.

Orthopedic Treatment

The use of cuff-based extension shoes on foals for treating flexural deformities is an efficient and beneficial method to improve flexural deformities, but harmful side effects can occur if applied inappropriately. That is why this orthopedic treatment is controversially discussed.

On the one hand, toe extensions applied to provide a lever arm using a shoe or composite material could be contraindicated because they may exacerbate wall separation in addition to delaying breakover. However, this risk decreases the older the foal. After 1 week, the suspensory apparatus is mature. Before this age, extension shoes should be not applied.

In addition, it is advisable to use short leverages the younger the patient is. Extensions may also contribute to lameness from excessive tension of the DDFT. The dorsal leverage exacerbates breakover and increases strain on the DDFT and more pressure on the navicular region causing discomfort and lameness. It must be judged carefully, if the application of extension shoes is necessary or if the use of a protective device applied to the toe to prevent bruising and subsequent lameness may be enough. In the context of the stated risk factors by using extension shoes in foals for correction of a club foot, the adaption of the management is crucial.

In the presence of lameness, it may be necessary for short-term elevation of the heels to establish weight-bearing on the involved foot and to relax the overloaded tendons and muscles. However, heel elevation is temporarily beneficial. It should be resumed to reach a normal hoof angle as soon as the foal is comfortable and bearing full weight. The hoof angle may be reduced gradually over a period of weeks to correct the toe angle step-by-step with less stress on the soft tissues.

In the author’s practice, none of the treated clubfoot cases showed wall separations or severe lameness during the treatment period. However, in cases that an extension shoe did not show a successful outcome after three applications, surgical interventions should be considered.

Acute side effects of the extension shoes application can also be a limitation of hoof expansion at the already contracted, narrow hoof that is caused by the cuff and glue. Long-term application of the shoes creates contracted heels and strain on the narrowed, growing coronary band, resulting in the coronary band bursting with spontaneous, bleeding cracks (Figure 1). Therefore, it is crucial to remove or change the shoes in an interval of 8-14 days.

A crack at the coronary band of a foal’s hoof after a shoe was applied 3 weeks earlier.

Images: Dr. Jenny Hagen

In addition, irritations and lesions of the coronary band can occur if glue reaches the sensitive skin at this region. The dermis can be burned with catastrophic consequences when the shoe is glued too closely to the coronary band or thinning hoof wall, or too much glue is used. However, most of the side effects can be avoided or minimized by an appropriate application of cuff-based shoes. The correct shoe preparations are explained in the following.

1. Shoe selection. The cuff should not be too narrow to avoid further narrowing of the hoof capsule and not too big to reduce the amount of necessary glue (Figures 2a-c). It is important to decrease the developing heat while the glue is hardening. In addition, the shoe should not be too short to provide sufficient support and not too long to avoid stepping in the shoe and pulling the cuff.

A size B2 Dallmer Cuff is an example of a synthetic and flexible extension shoe to correct a clubfoot in foals from the front, the side and the back.

2. Cuff preparation. The height and length of the cuff need to be shortened to provide some space between the shoe and the sensitive coronary band, as well as some freedom for the heels (Figures 3a-c). In addition, the cuff can be cut in the middle or in the quarter section to increase flexibility. This allows more expansion of the heels and improves the cuff’s fit. Moreover, burning holes in the cuff benefits the shoe application. First, excessive glue can escape and the final layer of glue has an optimal thickness to attach the cuff to the wall. Second, the cuff tightly connects with the glue and has more resistance against acting forces. For increased crack resistance, fiberglass can be mixed into the glue. Third, it improves the shoe’s flexibility.

Preparation of the extension shoe includes cutting the cuff and burning holes for better connection with the glue.

3. Hoof preparation. The hoof needs to be trimmed and cleaned before application of the shoe (Figure 4a-d). The bars should be removed to decrease as much restrictive mass of the hoof capsule as possible. The frog should be trimmed to healthy, compliant tissue to enhance loading. The wall through the quarters and heels should be lowered to the level of the frog. The region of the damaged dorsal hoof wall and sole should be cleaned carefully. Cracks, flares, wall separations or abscesses need to be disinfected and covered with protective material, so it doesn’t encounter glue. This can be easily accomplished by using a small piece of cotton in combination with Magic Cushion (rosin, turpentine, natural leather fiber and iodine). It is crucial to avoid contact between the Magic Cushion and the dorsal hoof wall where the glue needs to connect. In addition, gauze pads with Magic Cushion can be used to cover sole and frog to protect it against glue and to prevent the frog from rotting. The coronary band should be taped with duct tape or a bandage to avoid contact between the sensitive tissue and the glue. Finally, the hoof needs to be degreased with acetone-free solutions to enable optimal adhesion between the glue and hoof wall.

The hoof before trimming and cleaning viewed from the side and the sole (Figures 4a and 4c). Damage and wall separation of the dorsal hoof region becomes visible. The hoof after trimming the heels and cleaning the wall separation at the toe (Figures 4b and 4d).

4. Tool and material preparation. Before gluing the shoe, all necessary tools and materials need to be reachable next to the foal (Figure 5). These include:

The materials and tools that are necessary for the application of extension shoes include Magic Cushion (from top left), gloves, cotton, tape, cup, mixing sticks, glue, glue gun and prepared shoe.

• Gloves to protect your hands from the glue. It is advisable to wear two layers of gloves; one for working with Magic Cushion and another for working with the glue.
• Tape to protect the coronary band.
• Cotton and Magic Cushion to protect damaged regions, the sole and the frog.
• A cup and scoop to mix the glue.
• Glue, which can be differentiated between polyurethane-based and epoxy resin-based. The advantage of polyurethane glue is that it hardens quickly (1-2 minutes). The disadvantage is that it is stiff and has less crack resistance. The epoxy resin-based glue tolerates more shearing forces and has a better crack resistance; however, it needs 6 or more minutes to harden.
• A glue gun fitting to the cartouche.
• The prepared shoe.

5. Gluing the shoe. The cotton and Magic Cushion are placed at the sole and damaged areas (Figures 6a and 6b). Subsequently, the glue is mixed and applied at the inner side of the cuff. It is enough to put glue at the upper margin of the cuff. While pushing the shoe on the hoof, the glue distributes over the whole surface of the cuff. The escaping glue can be used to fill the holes and gaps. While the glue hardens, the limb should be lifted. Gentle and empathetic holding of the foal and its hoof usually makes the use of sedatives unnecessary.

Final application of an extension shoe in a foal with a clubfoot. Due to the holes, abundant glue could escape and connect with the complete cuff. Since the foal is kept outside a thin layer of glue was used to seal the dorsal margin of the cuff with the hoof.

Congenital Clubfoot

The congenital distal interphalangeal flexural deformity is recognized shortly after birth. Inherent deformities can range from mild to severe grades up to an inability of the foal to ambulate. Two distinct variations of clubfeet occur in neonates.

• Bilateral flexural deformity of the carpus combined with flexural deformity of the distal interphalangeal joint.
• An isolated unilateral deformity of the distal interphalangeal joint.

Examples of both situations will be described with the next cases.

Case 1: Bilateral Clubfoot 

As in the presented case, the bilateral deformity is more common in neonates. Usually, foals that show bilateral carpal flexural deformity with clubfeet require minimal to no intervention if they can stand, ambulate and nurse unassisted. In these cases, management is conservative because the primary carpal or metacarpophalangeal deformity, and thereby the clubfoot, resolves by loading the limb.

However, as in the presented case, a more severe flexural deformity of both front limbs requires therapeutic intervention, because the foal is not able to stand and nurse without aid. To support these foals, it can be taken that the earlier in the clinical course, the faster the resolution of the deformity.

In this specific case, the foal exhibited a severe flexural deformity with an angle of the dorsal hoof wall to the ground of more than 90 degrees. The broken forward toe axis caused a distinct instability. The deformity was so strong that the foal was initially not able to stand up, ambulate or nurse. For this reason, the owner initially applied two extension bandages to support the foal in the first days before the orthopedic treatment could be performed.

Unfortunately, this bandage caused too much pressure at the sensitive neonatal skin. Therefore, necrosis and skin lesions developed before the professional treatment of the clubfoot. The use and application of extension bandages will be explained in the next case. Still, the degree of flexural deformation decreased with this treatment and the foal was able to stand, walk and nurse. However, the foal was lame after 5 days due to bruises and wall damage of the dorsal aspect of the hoof (Figures 7a-c). The musculotendinous contraction was more severe at the left side. The improvement of the clubfoot condition was no longer in progress.

The left toe (Figure 7a), the sole (Figure 7b) and the right toe (Figure 7c) of a foal with a bilateral, congenital clubfoot.

As a result, an orthopedic intervention was performed at 7 days old by using hoof cuffs with dorsal extension without a reverse wedge (Dallmer cuff, size B2) (Figure 8a). It is strongly advisable to wait with this kind of orthopedic treatment until the foal is at least 1 week old, better older. The reason is that the suspensory apparatus of the distal phalanx is not mature before this age and the use of any kind of leverage before 1 week after birth might cause wall separations at the white line with sustainable hoof damage.

An extension shoe with a heel wedge was applied to the left hoof of a foal with a bilateral clubfoot, while a plane extension shoe was applied to the right.

At the more affected left side, the extension shoe was equipped with a plastic heel wedge to reduce stress and strain on the soft tissues (Figure 8b). This measure decreases pain and promotes relaxation of the musculotendinous unit. This type of foal shoe is made of flexible synthetic material and enables preparation of the cuff to allow more expansion of the foot. It is important to cut the height and the length of the cuff, so that the heels have enough freedom and there is sufficient space for the sensitive coronary band.

The heel wedge at the left side was gradually reduced by rasping the plastic material 2 mm every second day over 10 days. After this interval, the right foot was aligned and at the initially more contracted left limb, the same type of extension shoe without the heel wedge was applied for another 8 days.

Subsequently, the flexural deformity was corrected at both limbs. The toe was aligned and the hooves recovered from bruises and destruction. During the whole time, the foal was kept in a small paddock with firm ground. The foal developed to a sound yearling without sustainable flaws. The prognosis is good for an athletic use of this horse.

Case 2: Unilateral Deformity of the Metatarsophalangeal Joint and Distal Interphalangeal Joint

The second case shows a less common type of flexural deformity. The clubfoot conformation is not caused by a contraction of the musculotendinous unit of the DDFT, but a laxity of the extensor tendons (Figure 9).

A crooked foal that is 12 hours old presents with laxity of the extensor tendons in the left hind, causing an atypical type of a clubfoot.

This congenital limb deformity is often associated with difficult birth or mal-position in the uterus. Contrary to common practice, toe extensions are not beneficial and typically cause the foal to stumble. In this case, the foal was affected by crooked legs in the hinds combined with a severe clubfoot like toe conformation in the left hind. Due to the laxity of the digital extensor tendons in the left hind, the foal was not able to stand, ambulate or nurse without assistance. It was only able to stand for a few minutes, which is not enough to drink an appropriate amount of milk.

For this reason, 12 hours after birth, an extension bandage was applied for 1 week. The bandage was changed every 2 days to prevent lesions of the sensitive foal skin. The correct application of an extension bandage will be described in the following. The author is aware that this limb deformity is not fully fitting to the classical definition of a clubfoot conformation, but in the author’s opinion, this deformity and its treatment is of high relevance and should be described, as well.

1. Wrap the limb. The distal limb needs to be carefully wrapped in cotton to prevent pressure on the sensitive skin and the length of the cast material needs to be measured (Figure 10). The cast part of the bandage needs to reach from the proximal metatarsus covering the sole surface of the hoof and over the apex of the hoof.

The distal limb was covered with cotton that measures the length of the cast bandage.

2. Preparing the cast bandage. The cast bandage will be prepared in the measured length by wrapping the material around two spacers held by an assistant (Figure 11).

The cast bandage is prepared.

3. Applying the cast bandage. The cast bandage will be modeled and fitted to the shape of the distal limb and around the hoof (Figure 12). Do not push the cast too strong at the bulbs of the hoof. This causes pressure and skin necrosis.

The cast bandage is modelled on the foal’s distal limb.

4. Fixation of the cast bandage. The cast bandage is fixed with an elastic bandage at the distal limb. The stance surface can be enhanced with a layer of duct tape (Figure 13).

The cast bandage is covered with elastic bandages.

Directly after application of the extension bandage, the foal was able to stand, ambulate and nurse without assistance. After 4 days, it could stand without a bandage for a while and after 1 week, the limb deformity was solved (Figure 14a). Eight days after birth the foal was able to stand, ambulate and nurse without the bandage (Figure 14b). The angular deformities in the hinds were corrected with medial and lateral extension shoes. During the whole time, the foal had excess to pasture and was allowed to walk around without contact to other foals.

The crooked foal with a clubfoot in the right hind 4 days after application of the extension bandage (Figure 14a). The foal 8 days after birth (Figure 14b). The foal 4 weeks after orthopedic correction (Figure 14c).

Acquired Clubfoot

The most frequent form of clubfoot in horses occurs in suckling or weanlings at an age of 2-8 months. The development of an acquired flexural deformity can be described as a vicious circle.

Due to the upright toe conformation, the apex of the hoof wears and the upright nature of the foot becomes more evident. Subsequently, the hoof changes to a contracted shape and loses its flare as it grows distally. Furthermore, the dorsal hoof wall begins to dish and widens at the white line. Due to increased load at the dorsal weight-bearing margin, the toe may become bruised and ultimately abscess.

Because of the abnormal forces on the distal phalanx and inflammation associated with excessive loading, osteitis of the apex of the distal phalanx is a common complication. The destruction of the dorsal hoof region quickly results in severe lameness, causing a relief of the affected limb, which increases the flexural deformity. A fast and efficient intervention is required to prevent sustainable damages of the juvenile foot. Clinical management of these foals is dependent on the severity, duration and the etiology of the clubfoot, as well as the degree of lameness.

Case 3: Severe Clubfoot with Osteitis of the Distal Phalanx

The third case presents a 6-month-old foal with untreated clubfoot since it was 3 months old. The acquired flexural deformity of the right limb was caused by an excessive growth with contraction of the musculotendinous unit of the DDFT, causing discomfort and wear of the dorsal hoof region (Figure 15a and 15b).

Initial introduction of a 6-month-old foal with an untreated clubfoot (Figure 15a). Radiograph of the clubfoot with osteitis of the apex of the distal phalanx (Figure 15b). Damage and bruises at the dorsal hoof region due to excessive wear (Figure 15c).

The young horse was lame at the time of initial introduction for orthopedic intervention. The dorsal hoof wall was extensively damaged and the dorsal sole was almost completely worn with severe bruises. Radiological examinations showed distinct osteitis of the distal phalanx (Figure 15c). The hoof capsule itself was stable and wide at the heels.

In these cases, it is not enough to align the toe axis. It is also necessary to regenerate the hoof capsule and its enclosed structures. Therefore, the use of a hoof cast provides several advantages (Figure 16).

A hoof cast with heel elevation was made for gradual lowering and toe extension.

First, the extension can be modeled individually for the specific case. Second, the tension and strain of the extension is not just focused on the dorsal hoof region, but also at the whole hoof capsule, causing less load on the damaged areas. Third, and most important, if the cast is glued at the hoof wall and the limb is lifted during hardening of the cast, a kind of “external suspension” of the hoof is created, which is ideal for a maximum relief of the sole and the apex of the distal phalanx (see “One Option for Stabilizing the Hoof Wall After Resection” on Page 22 of the May/June 2022 issue of American Farriers Journal).

Fourth, initially, the heels can be elevated with the cast material to provide full ground contact of the hoof and to relieve the overloaded muscles and tendons. The owner was asked to rasp the cast material at the heels every second day over the interval of application. The aim was to gradually reduce the angle to reach a normal hoof angle without too much stress on the soft tissues. The process of cast application is the following.

1. Preparation of the hoof as described previously.
2. Clean and treat the damaged dorsal hoof region with disinfectant.
3. Cut a synthetic pad in the shape of the hoof and with the length of the required dorsal extension.
4. Cover the damaged hoof region and sole with Magic Cushion and cotton.
5. Apply glue at the hoof wall.
6. Place the fitted pad on the solar surface.
7. Wrap the cast bandages around the hoof and pad.
8. Lift the limb until the cast material is completely hardened.
9. Put glue at the dorsal, bearing surface of the cast as a protection against wear.
10. Remove the cast material around the coronary band and bulbs to avoid pressure at the sensitive tissue.

After three times of applying this type of extension hoof cast three times over 14 days, the sole and dorsal hoof region was recovered, the horse was not lame and the toe angle was sufficiently aligned (Figures 17-19). In addition, the foal was weaned from nursing and fed a bit less to reduce the growth rate of the skeletal system.

The clubfoot of a 6 months old foal at the initial presentation (Figure 17a), after the first casting (Figure 17b), after the second casting (Figure 17c) and after the fourth casting (Figure 17d).

The solar view of the clubfoot at the initial presentation (Figure 18a) and after the third cast application (Figure 18b).

Radiographs of the clubfoot at the initial presentation (Figure 19a) and after the third cast application (Figure 19b).

Sedation Unnecessary

During the last few years, the author almost never needed to sedate a foal to glue on shoes. It is a question of how to interact with the young patients. Even foals that have little experience with handling by humans usually behave well when the assistants and environment fulfill the demands of a calm and relaxed treatment of the foals.

It is absolutely contradicting to tightly lock and fixate the patients. They become scared and want to escape the situation. It is also not helpful to lift the legs too high and without freedom. The foals can hardly balance themselves and will not cooperate. Hold the limb shortly over the hoof, go with the movement of the foals and just in the moment of applying the shoe it needs to hold still. While the glue is hardening, it can move the limb as long as it does not run away. In some cases, a licking bowl can help to distract the foal. Usually, it is enough if one person holds the foal at the halter and one person is just standing behind it to limit the range of motion.

Foals can be handled in the lap of a sitting person (Figure 20a) or laid down in a stall with a cover over its eyes (Figure 20b). Sedation is not necessary.

Foals younger than 1 week can be laid down in the stall with a cover over the eyes and two persons holding it. Small foals, not able to stand because of the limb deformity, can be supported by using a dog harness to gently lift it. Or they can be placed on the lap of a sitting person with the legs hanging free.

Whatever you do, be gentle, calm and patient with the foals.