To understand navicular syndrome you should know the function of the navicular bone. The first function is to protect the joint and tendons from pressure and concussion and the second is to act as a valve for blood flow to the coffin bone and corium inside the hoof. Dr. David Ramey states, If the hooves are not properly cared for, the navicular bone becomes immobile, resulting in poor blood within the hoof. Damage and/or breakdown to the navicular bone and related connective tissue structures results in pain and a visible stumbling gait. Navicular syndrome often begins as an inflammation of the bursa between the deep digital flexor tendon and the navicular bone of the foot.

Navicular syndrome is caused by a gradual deterioration of the navicular bone at the back of the horses foot, near the heel. Breeds that have small feet compared to or related to their body size are more likely to develop navicular disease. The reason is the smaller the hoof in relation to the horses size, the greater the shock to the navicular bone. A horse with more upright pasterns may be predisposed to navicular syndrome. Overweight horses with smaller feet (proportionate to the size of their bodies) will have a higher probability of suffering from navicular syndrome.

Activity level can play a role in the development of navicular syndrome. Horses that are participating in stressful activities that they are not suited for, and experience a fair amount of percussion on the forefeet, are inclined to experience navicular syndrome. Improper shoeing can cause many joint and muscle problems and is a major factor in the progression of degenerative disease. An experienced farrier can use corrective shoeing to help manage the problem.

Signs of Navicular Syndrome:

• When walking the horse places his weight on his toe to avoid placing pressure on the heel area, which is the inflamed navicular bone.
• While standing, the horse will tend to swift its weight constantly, trying to relieve pressure and pain from the heel area.
• While traveling the horse will place his weight on his toes thus producing a rough gait and giving the appearance of being lame in the shoulder.
• The horse will often be lame after work, but look fine after a period of rest.
• The heels and adjacent hoof may become smaller and contracted as a result of poor circulation in the foot.

Contact your veterinarian when signs of lameness appear. Your veterinarian will probably use hoof testers to help diagnose the condition. By applying pressure over the frog area the hoof testers will produce pain if the presence of navicular syndrome is there. The hoof testers should be used on the hind feet as well, to compare the reaction with the forefeet.

An anesthetic injection can be given locally to block the nerve supply to the affected area, which should relieve the pain for a short period of time. If the horse was lame before the injection, and then walks normally after the injection, it may be assumed that the lameness is located in the navicular area.

Treatment for Navicular Syndrome varies and is dependent upon the demands put upon the horse and the severity of the condition. There are many ways to relieve the pain of navicular disease:

• As a preventive measure each horse should be trimmed according to the particular conformation that needs correction. The most effective treatment for Navicular syndrome seems to be good foot care. Corrective shoeing is helpful in relieving the pressure on the heels. Consult your veterinarian and farrier together when shoeing your horse.
• Medications can be prescribed for horses with navicular syndrome. Oral and injectable drugs are available to temporarily manage the pain.
• Neurectomy is a drastic treatment, usually used only for long-term cases after all other options are exhausted. A small piece of the nerve that penetrates the navicular area in the pastern is cut, numbing the entire foot. There are problems that are associated with this type of procedure that should be discussed with your veterinarian.

Better diagnostic tools for imaging the horses hoof are available and are important to the proper diagnosis of navicular disease. No other lameness in the horse arouses such a variety of opinions about definition, diagnosis, and treatment than does navicular disease. Dr. David W Ramey writes, "Most likely no condition of the horse's limbs is as feared by horse owners as is navicular syndrome. Probably no condition is as frequently suspected as a cause of lameness in the horse as disease of the horse's navicular bone. Certainly, few conditions that cause lameness in the horse are as frequently diagnosed as is navicular syndrome."