Definition - Navicular disease is a soundness problem in horses, more accurately called “navicular syndrome” as opposed to a “disease”. Navicular disease most commonly describes an inflammation or degeneration of the navicular bone and its surrounding tissues on the front feet. Navicular disease can lead to significant and even disabling lameness.

Causes - There can be several contributing factors to the development of navicular disease. Most research suggests that navicular disease is most commonly effected by the following factors:

Genetics - Horses with large bodies and smaller hooves(which is usually associated with smaller coffin bone, navicular bone, etc...) are less able to disperse their weight with such a small contact area.

Diet - A horse with an inadequate nutrient supply overall may be more likely to develop bone complications (and other metabolic disorders) which contribute to navicular disease or navicular complications. Some horses are simply predisposed to contracting navicular disease or other complications through an inability to process certain nutrients, etc...

Conformation - Most commonly horses with long toes and low lying or “under run” heels tend to exhibit more symptoms of navicular disease than horses with a more evenly balanced hoof. Other contributors to navicular complications are upright pasterns, small feet, narrow and upright feet are also typical candidates. It is best to choose a reputable farrier who has had experience with horses suffering from navicular complication.

Activities - Anything that causes excessive stress such as working on steep hills, galloping, jumping, quick turns and fast cutting all contribute to navicular disease, as they place greater stress on the DDF tendons, and may cause over extension of the pastern and coffin joints. Regular exercise on hard or irregular ground increases concussion on the hoof, increasing the risk of navicular disease. It is possible that standing can increase the chance of navicular disease (such as a horse that spends most of the day in a stall with little turnout, usually seen in racehorses and some show horses). This is because blood flow to the hoof decreases when the horse is not in motion. The horse is also constantly applying pressure to the navicular bones.

Body Weight - Horses with a high weight to foot size ratio may have an increased chance of exhibiting symptoms of navicular disease, since the relative load on the foot increases. This might explain why navicular disease is seen more frequently in Quarter Horses, as opposed to lighter breeds such as ponies and Arabians, for example.

Due to strain and inflammation of the ligaments supporting the navicular bone, reduced blood flow and increased pressure occurs within the hoof. Heel pain is very common in horses with navicular disease. Lameness may begin as mild and intermittent, and progress to severe lameness.

Horses affected by navicular disease tend to land toe first in an attempt to place more weight on the toes due to heel pain. They may occasionally or frequently stumble. The lameness may switch from one leg to another, and may not be consistent. Lameness may occurs in one or both front feet, although one foot may be more sore than the other.

Lameness from navicular disease can be more evident when the horse is worked on a hard surface or on a circle. After several months of pain from navicular disease, the feet may begin to change shape, especially the foot that has been experiencing the most pain, which tends to become more upright and narrow.

Treatment Options - Until now treatment options have been limited for addressing navicular disease. Traditional treatments result in little to no structural progress in either halting or reversing navicular disease, but rather focus toward increasing the horses comfort and ability to cope with navicular disease have emerged.

If you suspect your horse has navicular disease (or another bone related issue) we suggest you approach the issue with a three part process:

1. Make an appointment with your veterinarian for a diagnosis. Through the use of radiographs, nerve blocks and other diagnostic measures your vet is the person best equipped to tell you exactly what is causing the problem.
   
   
2. Have your farrier and/or veterinarian consult for recommendations in changes to shoeing
   
   
3. Contact TLC Animal Nutrition for suggestions about exactly what nutrients will work best for that particular problem. If the problem is bone related, such as navicular disease, bone spurs, calcium deposits, ringbone, degenerating coffin bone, etc... then TLC’s COMPLETE Dense Bone Growth program should be your first choice.

This unique blend, manufactured by TLC Animal Nutrition, Inc., is given anytime you wish to improve the integrity of bone. Calcium deposits, bone spurs, splints, fracture or navicular disease could be your worst nightmare. If the horse has an existing bone complication, feed COMPLETE Dense Bone Growth to increase the supply of bone building nutrients, support metabolic function in the body and increase blood circulation to assure that the nutrients reach their targeted destination successfully. Customers generally report more comfortable horses in as soon as 4 weeks, with the typical course of the therapy lasting 5 months. Results may vary.

Exercise - Horses with navicular disease need a work schedule that is less intense. Their fitness can be maintained by slow long-distance work or swimming, as opposed to being worked at high speeds, up steep hills, on hard surfaces, irregular terrain, or deep footing. Reducing the frequency of jumping is also important.

Hoof Care - The issue of hoof care is subject to much debate. Corrective shoeing has shown beneficial to horses suffering from navicular disease. Corrective shoeing can help to relieve pressure on the navicular bone. When the horse is more comfortable they will tend to be more mobile. The increased movement supports increased circulation, which is a good thing for horses with navicular disease. Choosing the correct shoeing method should always be a collaborative effort between an individual and their farrier depending on the horses particular conformation.

Medication - Isoxsuprine hydrochloride is the most commonly prescribed medication by vets for navicular disease. The methodology through which it works is by increasing circulation. There are also anti-inflammatories, corticosteroids and other injections which work to reduce pain and inflammation in the short term, but haven’t shown to address the issue at the root, bone loss. Glycosaminoglycans, such as glucosamine hcl, have been shown to decrease pain in some horses with navicular disease. Glucosamine is used by the body to build healthy cartilage & MSM has been used successfully for reducing inflammation. If you see an improvement with these products in your horse with navicular disease, you can assume the horse also has these problems as these items are not meant to improve bone integrity. To improve bone integrity you will need essential bone building nutrients that the body can use for repair(just like the nutrients msm and glucosamine are used for soft tissue repair in cartilage and other tissues). To add these bone building nutrients TLC’s COMPLETE Dense Bone Growth is your best option.

Surgery - In the procedure known as palmar digital neurectomy, the palmar digital nerves are severed, so the horse loses sensation in the back of the foot. This procedure should only be performed if it will eliminate the lameness associated with navicular disease, and only after all other options have been explored. The procedure is usually performed on both front feet. Complications can include infection of the wound, continuation of the lameness (if the nerves regrow or if small branches of the nerves are not removed), and rupture of the deep digital flexor tendon. After the neurectomy, if the horse becomes injured in the area the injury may go undetected for a long period of time, which risks the animal's health. Due to this, the feet should be cleaned and inspected regularly. Neurectomy tends to lower the market value of a horse, and may even make the horse ineligible for competition. It is best to speak to your vet if you consider it as an option. The most common misconception about "nerving" a horse is that it will permanently solve the lameness/pain issue. In fact, though the time periods vary based on the individual horse and surgical method utilized, these nerves will often regenerate and return sensation to the afflicted heel region within two to three years.