Club feet in foals: diagnosis and management
Figure 1. Club foot, stage I deformity
Figure 2. Club foot, stage II deformity
Figure 3. Toe extensions
“Club foot” refers to a limb deformity where the hoof has a very upright appearance with a long heel (see Figure 1). This condition is also known as “contracted tendons,” and it is one of the most common tendon deformities in foals. Anatomically, the deep digital flexor tendon (DDFT) is proportionally shorter than the bones, causing a deformity in the limb by pulling on the coffin bone (bone in the hoof).
The typical hoof conformation seen in these foals is caused by the downward rotation of the tip of the coffin bone by the DDFT. The severity of the rotation is classified as stage I or stage II. A stage I deformity is present when the front of the hoof is less than vertical or vertical (Figure 1). With stage II contracture, the dorsal hoof wall passes beyond the vertical (tips forward) (Figure 2).
In general, the forelimbs are more commonly affected than the hindlimbs. In most cases the problem is seen in both forelimbs, one of them being more severely affected. If the deformity is present at birth, it is referred as congenital deformity. This type of deformity occurs within the mare's uterus and is likely due to multiple factors. Acquired flexural deformities are those that develop after birth. In these cases, the bone grows at a faster rate than the tendon. Foals are more susceptible if they are nursed by heavily lactating mares, have a genetic tendency to grow quickly and/or are supplemented excessively with concentrates (proteins, carbohydrates, minerals or vitamins).
Newborn foals with severe congenital deformities may be unable to stand up and nurse appropriately. Prompt medical treatment is needed. Oxytetracycline, pain relief and splinting or casting are used to relax the tendons. Trimming or rasping of the heel helps to stretch the tendons and may be combined with toe extensions (Figure 3). Mild cases of contractural deformities respond to this treatment with complete correction. In more severe cases, surgery is required to obtain a positive outcome.
In cases of foals with acquired flexural deformities (from 3 months to 3 years of age), a balanced diet needs to be implemented and suckling foals should be weaned. Exercise is also important to the recovery process. As with the congenital contractures, these young horses must be able to stretch their tendons to correct the problem, but pain can often be associated with stretching. Analgesics are often needed to encourage exercise and stretching. Trimming of the excess heel and toe extensions are recommended to promote stretching of the tendon. Surgery is used for severe cases and for cases that are not responding to medical treatment and corrective shoeing. The treatment of choice for stage I club feet is cutting of the check ligament of the DDFT. This ligament acts as a “check rein” on the tendon and the surgery allows more stretch. This procedure also needs to be combined with analgesics, physiotherapy and orthopedic trimming/shoeing to achieve the best possible result. Young horses respond better than older horses but it can be done at any age. Severe stage II contractural deformities require cutting the DDFT for a successful correction. This treatment was initially considered as a salvage procedure; however, several horses have turned into sound riding horses after the surgery.
The prognosis for foals with mild to moderate “club feet” that are managed appropriately is good. The earlier treated the better the prognosis. Those treated before 6 months of age had significantly higher success rates. In severe cases, the prognosis remains guarded. Horses that don't respond to treatment tend to have more coffin joint pain and hoof deformities due to the upright hoof conformation.