Description

The pedal bone is a single large bone in the horse's foot with the smaller navicular bone behind it. Fractures of the pedal bone are usually stress-related. They tend to occur in the front feet of horses that kick at solid walls or other hard objects and in feet of racehorses that are exercised on hard surfaces.

Depending on the type of fracture, horses may exhibit an acute non-weight bearing lameness or the lameness may be more moderate. Since the pedal bone is hidden within the cavity of the hoof, the best method of diagnosing the existence and the extent of the fracture is through the use of X-rays.

When a pedal bone fracture is diagnosed quickly and treated correctly, the prognosis for complete recovery is excellent.

Symptoms

• Moderate to acute supporting limb lameness
• Increased digital pulse
• Swelling around the coronary band
• Sensitivity to hoof testers

Causes

Fractures to the distal phalanx, often referred to as the pedal bone, are usually caused by a stress injury. Either the horse kicks a stationary hard surface, such as a concrete wall, or the injury occurs while the horse is exercised on a hard surface or in the course of jumping. Trotting on a hard surface will usually accentuate the lameness caused by the fracture.

Occasionally, a pedal bone fracture will be caused by penetration of a nail or a sharp stone. Pedal bone fractures sometimes mimic other common conditions such as abscesses or severe bruising. When X-rayed, the fracture may appear as a hairline crack that may be difficult to see. Sometimes another X-ray taken several days later will give a better picture because the bone usually dissolves close to the fracture.

Prevention

Pedal bone fractures are difficult to prevent. Making sure the horse is properly shod, paying quick attention to a horse's tendency to kick walls or other hard objects, and avoiding exercise on hard surfaces will help minimize the chances for these fractures.

Treatment

The first step in treatment is to confirm the suspected fracture and determine it's extent through an X-ray. If the diagnosis is made quickly and appropriate treatment initiated, most pedal bone fractures in young horses should heal well with little or no residual lameness. .

Initial stall confinement for a length of time determined by the veterinarian, and then progressive exercise until the bone is healed is sometimes all that is needed, especially with horses less than a year old.

Older horses will require more attention and time for satisfactory healing of the fracture. Stall confinement for a longer period of time, a program of nonsteroidal anti-inflammatory drugs, and therapeutic shoeing are recommended by most veterinarians.

In some cases, surgery may be necessary to remove small bone fragments. Nerve blocks to deaden pain are not recommended because a pain-free horse may place excessive pressure on the fractured pedal bone. Having weight placed on the affected hoof can displace the fracture and lead to a longer healing time.