When a horse is lame, it means they have a gait or a stance that is abnormal for their breed. It is caused by an issue with the structure or function of the horse’s locomotor system. Because of that disorder, the horse is unwilling or may be unable to stand or make normal movements.
It may be caused by an injury, an acquired disorder, a genetic disorder, an infection, a disease of the central nervous system, a circulatory disease, or a metabolic disorder. It is the most common cause of loss in use.
Lameness, however, is not an actual disease. It is a symptom caused by another health issue that is affecting the horse. Pain is the most common reason why horses become lame, but anything that changes the structure or function of the locomotor system offers the chance for lameness to occur. That is why finding the cause of the lameness and treating the root issue is so critical to the recovery of the horse.
Determining Lameness on a Scale of Severity
To help determine the severity of lameness with individual horses, the American Association of Equine Practitioners has created a grading scale. This scale provides criteria that applies to all breeds so the same standards of evaluation and treatment can be applied to every horse. That makes it easier to describe the lameness and begin the process of developing an accurate diagnosis.
There are six grades that are included on the current lameness scale.
Grade 0: This is a sound horse that is not experiencing a lameness issue whatsoever.
Grade 1: This is a horse that experiences intermittent lameness that may be difficult to observe. The horse, even when exhibiting symptoms of lameness, may show only subtle changes in gait or stance.
Grade 2: This grade represents a horse that shows consistent signs of lameness under specific conditions. The lameness may not be apparent when the horse is moving in a walk or a trot along a straight line.
Grade 3: This is a horse that shows lameness symptoms that are consistently observable under every circumstance during the trot.
Grade 4: This horse displays consistent lameness during the walk.
Grade 5: Horses with this grade of lameness can only place a minimal amount of weight on a leg or hoof while in motion or at rest. Horses with this level of lameness are often unwilling or unable to move.
What Are the Common Causes of Lameness in Horses?
Although there are countless ways for a horse to experience lameness, there are certain causes which are more common than others. Here are the most common issues that veterinarians see which cause lameness in horses.
#1. Heel Pain
Anything that causes pain to the heel of the horse offers the potential for lameness to develop. This can range from an injury to one of the ligaments to problems with the coffin bone. Heel pain can be caused by a hoof wall problem as well. It is also a symptom of navicular syndrome in horses.
#2. Degenerative Joints
For older horses, degenerative joint disease is a common reason why lameness occurs. It can also occur in highly active sporting horses. Excessive wear on certain joints can prevent the cartilage from being able to repair itself, which causes pain for the horse. When enough pain is present in the leg, the horse may refuse to move.
#3. Ligament and Tendon Injury
Any injury to a ligament or tendon in the leg provides a degree of risk for lameness to develop. One of the most common causes of lameness in this category involves the upper digital flexor tendon since it has such a superficial placement. The suspensory ligament and the deep digital flexor are commonly injured as well and can create lameness.
An abscess on the foot can cause various grades of lameness, depending on the severity of the condition. Caused by an infection just beneath the hoof, the abscess places pressure on the sensitive structures of the foot and can even cause those tissues, such as the frog, to begin to degenerate. Without relief, an abscess tends to grow and make the lameness worse over time.
#5. Navicular Syndrome
Heel pain is not always present with navicular syndrome, but this small bone can cause lameness nonetheless. This small bone lies within the hoof and if it is not positioned correctly or there is an issue with its health, then it is very likely that the horse will suffer from lameness on some level.
How to Determine What is Causing Lameness
Because there can be so many different causes of lameness in horses, trying to find the specific cause through a systematic investigation and be time consuming and difficult. To make the process easier, a thorough examination of the horse’s medical history is usually the first step in the journey toward a diagnosis. The age, breed, type, and training of the horse will be examined as well as they can provide clues as to what is causing the lameness.
In some horses, an adverse reaction to shoeing can be the cause of lameness. A shoe that is attached poorly or has nails driven into a sensitive portion of the foot may show no outward signs of injury, but can cause high levels of discomfort for the horse. Knowing when the last shoeing took place is usually part of the interview process. In most cases, the shoes will need to be removed to complete the examination.
To relieve pain for the horse, a veterinarian may prescribe certain analgesics or anti-inflammatory medication. How the horse responds to those medications may determine the treatment plan for lameness as well.
A visual inspection of the horse and palpitation of the limbs in various positions can provide a lot of information about what is causing the horse’s lameness as well. If the physical examination is inconclusive, diagnostic imaging technologies can provide supplemental information that may shed light on the situation.
To localize lameness to a specific limb, most horses must be exercised during their examination. If localization occurs, a regional anesthesia may be administered to determine the horse’s response. Exercise is not an option for horses that may be suffering from a leg fracture as the cause of their lameness.
A complete inspection of the back and neck should occur as well.
By recognizing lameness, it can be diagnosed and treated. Because the only symptom of lameness may be a head nod or a rising of the neck when an injured limb strikes the ground and bears weight, an experienced veterinarian should evaluate the horse and recommend a treatment plan to restore the horse to good health.
How to Treat Lameness in Horses
There may be simple steps that can be taken immediately to resolve a lameness issue with a horse. The first step could be to pick the horse’s feet as this will remove any rocks that may have wedged their way into a hoof crevice. Look for bruising on the sole of the foot and check for any discharge. Cracks may be in the hoof or it may have been trimmed too short.
If you feel warmth in one hoof, but not the others, then this can be a sign of infection or an abscess. A pounding pulse may be present as well.
Should inflammation be present, it is important to encourage the horse to get some box rest. This will encourage less weight to be placed on the inflamed or painful area and encourage the horse’s immune system to work on an infection that may be present.
If swelling is present, a veterinarian may recommend cold hosing on the affected area. This, along with anti-inflammatory medication, can help to reduce localize swelling. You may need to protect the hoof of the horse to prevent it from softening with this daily procedure. Soaking an affected hoof in hot, clean water with Epsom salts can help to draw an infection out and provide temporary relief to the horse.
For abscesses that cause lameness, keeping them warm can help them to mature more quickly with a lesser degree of pain to the horse. If the abscess bursts, disinfect the wound and keep it clean so that it can heal properly.
A trip to the farrier may also be necessary to restructure an affected hoof so that it can bear weight once again. New shoes, braces, or glue-on products may be able to relieve the pain the horse is experiencing so they can become active again.
Lameness can be difficult to diagnose. It can also cause potentially life-threatening circumstances if the grade is severe enough. That’s why being proactive with foot care is essential to the health of the horse. It may be impossible to prevent all potential injuries. With proactive observation and care, there are many cases of lameness that can be avoided in horses today.