As the saying goes, “no foot, no horse.” Most horses have jobs that require athleticism. Additionally, a horse with a severe lameness on one leg cannot survive for very long without causing irreparable damage to at least one of the other limbs. Knowing what causes leg injuries in horses, how to identify lameness, and when to call your veterinarian are keys to saving your horse’s athletic career and potentially its life.
What Are Leg Injuries in Horses?
Leg injuries in horses occur when any one or more structures in a horse's limb is damaged by inflammation, infection, or trauma. This results in pain that can manifest as limping or lameness. Injuries can either be acute, meaning they happened very recently, or chronic, meaning the injury developed over time. A good example of an acute injury is a hoof abscess, while arthritis in a joint is more of a chronic condition.
Another way to think about leg injuries is considering what body structure may be affected. A little anatomy knowledge goes a long way to understanding the most common leg injuries. Horses have evolved to bear weight on one digit of each limb, and all muscles that control movement are in the upper limb. That means that muscles above the knee in the front and the hock in the back attach to tendons and control flexion of joints. This allows for the finely tapered and fast-acting limbs of the horse, but these tendons and ligaments that run alongside are prone to injury.
Additionally, these critical ligaments and tendons, along with nerves, blood vessels, and joints, are very close to the surface and often are involved in a wound. What may look like a minor cut may involve a critical structure.
Finally, and most commonly, are injuries contained within the hoof. The hoof is a rigid capsule, meaning any inflammatory process causing swelling within will result in painful pressure. Think of a blister under a fingernail—ouch!
Symptoms of Leg Injuries in Horses
Most owners know when their horse is lame, but identifying the affected limb can be difficult if there is no obvious wound or swelling. A step-wise approach to assessing a horse should be taken to distinguish the affected limb and between the following symptoms of lameness safely:
First, watch the horse as it is standing still. If it is severely lame, it might stand with the hoof tipped up on the toe without wanting to bear any weight on the sole of the foot. Another sign is that it might stand pointing the hoof forward of the normal standing position, called “pointing.” Sometimes a horse will try to point with both hooves and rock backwards.
Secondly, feel your horse’s limbs. Many common hoof injuries cause the foot to be palpably hot. Pick up the foot to ensure your horse hasn’t stepped on something like a nail; if you see one call your veterinarian immediately for further instruction without pulling out the object. If the nail may penetrate the sole further unless removed, remove the nail after taking photos of its exact location to assist in veterinary treatment. This treatment may include radiographs to assess damage and a tetanus vaccination. Feel up your horse’s limbs for swelling over joints, within tendons, or over the whole leg.
The skin on the legs is very thin, and horses can often get caught up in fencing or kicking through stall walls. Small pieces of fencing may cause small puncture wounds. Even major wounds can be treated with prompt medical attention. Always practice safety when feeling for swelling or cuts; even a good horse may react strongly if it is painful.
Finally, if your horse is not severely lame, watch it walk and trot on a loose lead over firm, level ground. If the horse is lame on one front leg, the horse will nod its head. You can determine which leg is lame by carefully noticing when the head goes up and which leg has hit the ground at that moment. The horse will dip its head downward as the sound (non-lame) leg hits and conversely lift the head as the lame leg contacts the ground. There may be no head nod if a horse is lame on both front limbs; its strides instead will be choppy and short.
If the lameness is in the hindquarters, the horse will drop or raise the hip more on the side that is lame when viewed from the back. A normal horse should step with his back foot into the hoof print left by the forelimb (tracking), and so evaluating your horse for a shortened stride from the side may also help in localizing the lameness.
Causes of Leg Injuries in Horses
When looking for the site of injury, start with the hooves and work your way up. Only evaluate your horse at a walk and trot if it can put some weight on the affected limb. Some of these causes will result in lameness that still allow the horse to stand weighted on all four legs, while others are emergencies because they result in non-weight bearing lameness. The latter are starred with an asterisk below
- Injuries to the foot
- Sole bruising or tender soles after an aggressive trim
- Foot abscess*
- Penetrating trauma*
- Navicular syndrome
- Injuries to tendons and ligaments
- Strains (bows)
- Traumatic cuts to tendons and ligaments*
- Injuries to joints
- Osteochondral fragments (bone chips)
- Penetrating trauma*
- Swelling over a large part or the entire limb
- Infection in the skin and abnormal lymph drainage (cellulitis)*2
- Major bone fracture*
Diagnosing Leg Injuries in Horses
Your veterinarian will perform a lameness exam, starting with the steps described above. They’ll also apply hoof testers where the foot is pinched with a specialized tool to localize lameness.
If the site of lameness isn’t obvious from the initial exam as your horse is standing still, walking, and trotting, your veterinarian may recommend temporary nerve blocks. Nerve blocks use a local anesthetic (lidocaine or similar drug) applied just under the skin to desensitize an area. Again, because horses don’t have muscles in the lower limb where most injuries occur, these only serve to relieve pain for diagnosis and won’t affect your horse’s natural ability to move.
Once the lameness is localized, your veterinarian may recommend imaging such as ultrasound or x-rays. Advanced imaging like MRI and CT are available for horses, but are usually reserved for hard-to-diagnose cases.
Treatment is very disease-specific and will be well-detailed by your veterinarian. At-home care may consist of stall rest, pain relief with drugs such as phenylbutazone, and bandaging or wrapping limbs. Horses with wounds or cellulitis will often receive antibiotics. Some causes of lameness require specialized farrier work, while others need to be treated at a hospital or even have surgery. It is good practice for owners to know how to put on a routine leg wrap or bandage in case the need arises while waiting for their veterinarian.
Prognosis for Horses with Leg Injuries
Many of these causes of lameness will heal with appropriate management. As always, it is very important to follow your veterinarian’s recommendations.
How to Prevent Leg Injuries in Horses
The hoof is the most common site of lameness; keeping your horse’s living area clean and free of debris is critical to foot health, as is regular farrier work. Maintaining high-quality feed and an appropriate body weight are also key for whole-horse health, including limbs. In regard to exercise, regular routines with gradual increases in time and effort will promote athletic longevity.