Broke Leg Lameness...but is it broke?
The 3 legged horse may be one of the most feared creatures of the equestrian community... because, well, horses are not meant to live a 3 legged life. As prey animals, they require strict use of all 4 legs. The good news is that prognosis is not always poor for a 3 legged lameness and not every 3 legged horse has a broken leg. The first step is to determine the causes of the lameness so that appropriate treatment can be initiated. The most common causes of 3 legged lameness include:
1. Foot abscess: Foot abscesses occur most often during the wet months when the foot is soft. How does an abscess end up inside the hoof? The abscess is often preceded by a bruise which then becomes infected due to translocation of bacteria from the soil. Weakening in the white line can also allow for bacteria to track up into the foot. The pus becomes trapped within the hoof capsule which causes severe pain. Symptoms of a foot abscess include lameness, increased digital pulse (throbbing in the arteries that run near the foot), heat, and mild swelling of the pastern. An uncomplicated abscess will rupture through the white line but not all abscesses follow the rule book. They can also rupture from the sole (subsolar abscess) or from the coronet band. These can be more difficult to treat. Initial treatment for a foot abscess includes soaking and bandaging the foot with a poultice or drawing salve. If the abscess persists, x-rays, antibiotics, anti-inflamatories and/or therapeutic shoeing may be required. Starting treatment early on will simplify treatment and prevent complications from arising. Veterinary examination of the foot will help identify where the abscess is located and which treatment option is best.
2. Septic joint: Septic joints are a life threatening condition in the horse. History of a septic joint usually involves a penetrating wound (although in foals it can occur from blood stream infections). The wound may be large and deep or very small and unnoticeable. With a septic joint, horses are non-weight bearing 3-5 days after incurring the injury. Bacteria enters the joint space and creates an inflammatory reaction that is very painful. Treatment for a septic joint is surgical lavage and intensive antibiotic therapy. Any horse with a wound at or near a joint should be treated as an emergency. Swift diagnosis and treatment can improve the outcome.
3. Broken leg: The equine leg contains little muscle to protect the bones that run to the foot. This allows the horse to gallop fast but presents a high risk for fracture when faced with trauma. With fracture, there is usually swelling, abrasions, heat, and pain to the touch. X-rays may be required for a definitive diagnosis. Prognosis depends on the bone that has been fractured and the surgical options that exist for stabilizing the fracture. Immediate immobilization and imaging should be performed in any suspected fracture.
4. Nerve damage: A less common causes of 3 legged lameness is avulsion of the brachial plexus or damage to the nerves that run to the leg. Horses that have a brachial plexus avulsion will appear to have a broken leg but there will be no swelling evident in the limb. They often drag the leg rather than hold it up. Prognosis is guarded depending on the severity of the nerve damage. Treatment is aimed at controlling inflammation and providing supportive care. Many of these horses become recombent and are unable to stand.
