You may know it as Navicular Disease, but progression of medical knowledge makes this an inappropriate name, as is Navicular Syndrome. The best name we have for now is Caudal Heel Pain Syndrome, which usually causes lameness in a horse. Addressing Caudal Heel Pain Syndrome will require professional veterinary assistance. Learning about navicular problems can be helpful to help your horse through treatment, or if your horse has no symptoms, helps to prevent your horse from enduring such an injury.
Your horse will always be prone to scrapes and injuries, as well as the more serious problems like Caudal Heel Pain Syndrome. Fauna Care’s healing sprays can’t cure navicular problems, but can help with the smaller injuries your horse may acquire. It’s reassuring to have access to immediate care that gives easy care to cuts, burns and other general injuries.
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The problem lies all in the feet. The navicular bone and all other vital components that influence the extent of pain are located in the feet. Navicular problems occur for varied reasons, not all fully explored and understood. Symptoms such as lameness are easy to spot however, which is important to leading to the next step of treatment.
There is a long tendon running from the bottom of the coffin bone up to the cannon bone, which is just below the knee. The function of the navicular bone is to give this tendon a gliding surface at the location in which the tendon changes angle.
The navicular bone is small and canoe shaped, located at the back of the horse’s heel. The navicular bone rests in the back junction between two larger bones named the coffin bone and the short pastern bone. Pain is caused when components of the foot -- such as the bones, bursa, tendons, and/or ligaments -- change in a way that hinders smooth functioning.
Your horse can develop navicular pain in a number of ways. Performance horses especially are prone to injury and inflammation of the supporting ligaments. The problem could also be in the surface of the flexor bone, or the flexor tendon itself. And of course it could be the navicular bone itself that is causing pain and lameness.
And what causes such stress on the feet for them to be impacted in this way? The cause of navicular problems varies, from type of exercise, to type of horse. Horses who exercise more frequently in activities involving front-leg impact -- such as jumping, reining, roping and cutting -- are generally more at risk. There are other theories suggesting causes may also come from an extreme stress and reduction of oxygen in the heel area. Providing your horse with shoes that reduce contact between the frog and the ground can be a cause, as well as irregular farrier care and unbalanced hooves.
Sometimes it has to do with the proportions of the horse. A horse with a heavy build and small hooves is more prone to navicular problem symptoms. Besides disproportionately small feet, a horse is also more at risk if they have abnormalities of the hoof such as a broken forward or backward hoof axis. Underrun heels, sheared heels, contracted heels, and mismatched foot angles also harm a horse’s chances of avoiding navicular pain. Most breeds have been impacted by navicular problems, but there are several who seem more prone to experience symptoms. These breeds include Quarter Horses, Thoroughbreds, and warmbloods. Age could be an influence as well, as most affected horses are between the ages of seven and 14.
The most common symptom of Caudal Heel Pain Syndrome is lameness. However there are other indications you can look out for. There can be a cause for concern when you observe any of the following warning signs:
The symptoms are often the horse’s attempts to ease pressure off the feet that are causing them pain. The front feet are often in different degrees of pain, so the foot that is causing more pain will be pointed, which means positioned slightly in front of the other forefoot, which alleviates pain by shifting weight off of the pointed foot. The horse will also try to lessen the pain by striding toe-first, which strays from the normal heel-first patten, which results in a stiff, short-stride gait. Lifting one forefoot will put all the pressure onto the other which can cause too much pain for your horse, making them unwilling to trimming and shoeing.
The first step is diagnosing the origin of pain. From there, treatment varies. Approaches to treatment include shoeing, medical, and surgical. Treatment can be unpredictable and should be handled conservatively, making changes slowly.
The vet must first make sure your horse’s heel pain is actually caused by Caudal Heel Pain Syndrome. Diagnosis involves a series of tests to determine the location of pain. The vet may use a combination of tests within the categories of flexion tests, hoof and frog pressure tests, nerve blocks, X-rays, scintigraphy, thermography, ultrasound, venograms, and magnetic resonance imaging (MRI). These tests will determine where the horse’s discomfort originates from, which is vital for providing proper treatment.
The tests are made to worsen the exhibited lameness in the horse to determine the affected area. Several tests are usually needed because one test does not successfully isolate one structure of the foot. For example, the hock flexion test flexes not only the hock flexion, but the stifle and hip joints, therefore an overlap of tests is needed to ensure it is the hock flexion causing pain.
Therapeutic shoeing is required when the cause of pain seems to come from a broken axis between the coffin bone and short pastern bone. Underrun and contracted heels should be corrected, and the angle of the foot should gradually be altered back to normal alignment. In order to maintain your horse’s foot health, there should be a rim of extra shoe, with nails kept as far forward as possible. You can also try trimming the toe, or raise the angle of the foot by applying a small pad.
Medication isn’t always the right path of treatment for your horse, but if you do choose medication, it will likely involve an anti-inflammatory drug such as phenylbutazone (Bute). Isoxsuprine is another common (and somewhat controversial) medication used to address the decreased blood flow. Pentoxifylline and metrenperone are also known to help with circulation in the foot, although these medications require further research.
Surgery is the most extreme treatment and should only be turned to as a last resort. Surgery is not a treatment but a procedure that relieves pain. The most reliable procedure is digital neurectomy, which has been performed for decades. The surgery involves cutting the digital nerve in the lower pastern area. This can be done simply by cutting the nerve with a scalpel, or using a high-tech surgical laser. The procedure may need to be repeated to establish soundness.
Caudal Heel Pain Syndrome can be avoided. There are simple daily practices you can follow to minimize your horse’s risk of navicular problems.
Uneven proportions of a horse can put excessive strain on the feet, which can lead to such problems. Avoiding obesity can be accomplished by providing your horse with proper nutrition and exercising them daily. Pasture intake can be limited by muzzling or dry-lotting horses, and they can be fed a low-calorie supplement pellet.
Proper hoof care is the key to maintaining foot health and avoiding navicular problems. A farrier should be frequently tending to your horses needs, ensuring the feet are carefully balanced and the hooves can function properly. Hooves should be able to expand when they make contact with the ground, and should be able to efficiently roll forward. A skilled farrier can also correct issues such as underrun, contracted, or sheared heels. Mismatched hoof angles or a broken hoof/pastern axis should also be addressed with proper hoof care.
Caudal Heel Pain Syndrome is unique to the horse, and care and treatment should be individualized. Your horse will be back on its feet and strutting its stuff once it’s been given time for rest and proper care.
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