Best Practices for Navicular Horses
by Ann Ramsey BS, CERA, APF-I
When we say a horse has ‘navicular’ it usually describes a horse with bilateral forelimb lameness. It’s important to understand that ‘navicular’ is really an umbrella term for many different pathologies that can occur at the back of the horse’s foot. Painful heels can be caused by anything from atrophy of the heels' soft tissue, tendon or ligament lesions, or changes to the navicular bone. The veterinarian must perform the necessary diagnostics to determine the real source of pain. This should include a full lameness exam and may require nerve blocks, x-rays, ultrasound and MRI assessments.
The movement pattern of affected horses will change in a predictable way; they begin to predominantly land toe first instead of heel first. Healthy horses will vary the landing and loading of their hooves. So while it is normal for a horse to toe load while going up hill, it should not be the predominant loading pattern. A toe first landing means a horse is avoididng pain at the back of the foot.
With a toe first movement pattern, horses will appear sound because they can travel evenly when both feet are affected. Unfortunately, the toe first landing can cause further pathology to develop. Dr James Rooney described how the compesatory toe first landing can exacerbate damage to the deep digital flexor tendon, and navicular bone.
Later, the horse will begin to use the neck in a problematic compensatory pattern. Horses can control how much force is loaded through the leg with the position of the head and neck.
Pictured above is a horse with tape running over the brachiocepahlicus and omotransversarius muscles. These muscles brace the head and neck and help the horse compensate with forelimb pain.
Lame horses swing the head up when the most effected leg lands. Bracing the under neck spares the horse about 300lbs of force seen by the tissues of the lower leg. Unfortunately with a bilatreral forelimb lameness, horses can engage the neck evenly on both sides, and apear sound. The neck and trunk of a horse diagnosed with navicualr disease, will need care as well as the feet. I recommend the horse bee seen by a vet who can perform an ultrasound to check for pathologies of the cervical vertebrae that may have developed over years of compensating.
Vet and Farrier Teamwork
Navicular disease treatment hinges on the collaborative care given by your vet and farrier. Working in tandem with the vet ensures the best diagnostics and ongoing pain management are being utilized. In addition, the vet can provide radiographs. Using radiographs is the best way to accomplish a nuanced therapeutic shoeing application, and the quickest way to get the horse's trajectory to improve.
Pre and Post Radiographs...The Key to Rapid Results
Before applying the shoe...
Using x-rays, I can ensure the horse has enough support in caudal foot with a dental impression material orthotic. I also check that I’ve set the point of breakover back where it needs to be. X-rays are a critical tool to ensure the horse improves. Shoeing is finished with a wide web composite shoe that offers more reinforcement to the sole body.
Using radiographs throughout the stages of shoeing allows for precise theraputic shoeing. Here, I trim the foot and apply the orthotic packing. This way any necessary changes to the foot can be made before applying the shoe
After Applying the shoe...
Hoof Care Solutions
I utilize different therapeutic approaches depending on the individual animal’s morphology and disease progression. I have had success using both shod and barefoot methods for rehabilitation. The most important goal is to restore comfort at the back of the foot. Hoof care is designed to facilitate a healthy heal first impact. For example, if a horse lacks hoof mass, I add supportive materials like custom orthotics and I choose materials that will help dissipate energy and absorb concussion.
Pictured above is a horse with navicular disease after application of a composite shoe with a custom orthotic made of dental impression material.
Contraction and Atrophy of the Soft Tissues
If a horse has contraction or atrophy of the soft tissue at the back of the foot, a barefoot approach that incorporates judicious use of boots and pads, along with graduated exercise can be very successful as well. The key is to offer a wide range of therapeutic tools and options depending on the individual animals' needs.
The above photo shows progress after 6 months rehabilitation of the atrophied soft tissues of the foot. This was accomplished with glue on composite shoes.
Conclusion
Today, vets and farriers have tools available that make navicular syndrome less painful for horses and less frightening for horse owners. The best defense against navicular disease is to catch it early. As a horse owner it is critical to learn to spot a toe first landing pattern and do something proactive to intervene. The sooner your horse’s caudal heel pain is resolved the better the chances of avoiding permanent damage.
Pain in the front feet can frequently be resolved, but keep in mind that the front feet are not the only structures affected by the disease process, the neck and thorax and forelimbs of the horse are also affected as they are recruited in compensation. These areas of the body can become painful and require treatment and therapies as well. Once the horse’s front feet are supported, I begin bodywork, targeted exercise and other rehabilitative techniques to further their care. For more on this see my other blog, “Neck Muscle Bracing”.