1. Navicular Syndrome Myria Shipman, Dr. Frank Flanders and Asha Wise
Navicular has been described as one of the most common causes of chronic forelimb lameness
Myria Shipman, Dr. Frank Flanders and Asha Wise
Georgia Agricultural Education Curriculum Office
Georgia Department of Education
February 2006

2. Disease or Syndrome?
Because there is no proven cause or treatment it is better referred to as a syndrome
Navicular Syndrome is generalized heel pain due to problems with the navicular bone
Other causes of heel pain are often misdiagnosed as Navicular Syndrome
Navicular was at first called a disease. Recently, researchers have begun to refer to it as a syndrome because:
Lack of a specific etiology-meaning there is no one specific cause that has been proven as resulting in navicular, rather it appears that there are several different causes
Lack of a specific treatment or therapy for navicular.
These days, you will hear it called both navicular disease or navicular syndrome but the two terms are used to describe the same thing.
Usually occurs in the forelimbs, rarely in the hind limbs.
Usually both forelimbs are involved, but one may be worse than the other.
Some of the other causes of heel pain: bruised heels, underslung heels and misbalanced feet.

3. Three Causes of Navicular
Concussion or trauma to the Navicular bone
Thinning and erosion of the cartilage
Degeneration of the Navicular bone
Injuries of the Navicular bone and surrounding areas
Arterial obstruction
strain and inflammation of the impar ligament can obstruct these blood vessels and reduce blood flow to and from the navicular bone
1a: around the navicular bone
1b: usually occurs in the advanced stages, after cartilage has eroded. Can be accompanied by adhesions between the bone and the deep digital flexor tendon.
1c: injuries that occur during locomotion can cause trauma to the area.
2. Blood flow can become decreased if the blood vessels to the navicular bone are obstructed.

4. *Osteoarthrosis (degenerative joint disease)
Changes in the Navicular bursa synovium
*Osteoarthrosis (degenerative joint disease)
Has been compared to DJD (degenerative joint disease) because of similarities in the changes that occur with each:
Degenerative changes
Increased pressure on the area
Bone remodeling response to the degeneration

5. Predisposing Factors Poor hoof conformation
long toes and low heels
narrow upright feet
Extreme work on hard surfaces
Standing in stalls for extended periods of time
Improper trimming and shoeing
Also, impact on the hooves will eventually lead to navicular. Horses that are trained to jump obstacles endure impact on the hooves every time they land off of a jump. Many jumping horses will eventually have navicular.

6. Symptoms Often a unilateral lameness
Usually restricted to the forelimbs
Walking toe to heel
Short choppy strides
Reduced wear of the heel region

7. Management Practices Medication Reduce intensity of training
vasodilators
anti-inflammatory
corticosteroids
Reduce intensity of training
Exercise program should be determined by the severity of problem
There are ways to manage pain but the horse will never fully recover

8. Corrective shoeing corrective trimming: raise heel, role toe
types of shoes : keg, conventional bar, egg bar, aluminum, rolled-toe (any of these can be combined with pads)
conformation of hoof and location of pain determines trimming and shoeing methods
Egg bar is pictured. Management of navicular horses can become expensive!

9. – Many times bone disorders are caused by an excess of Aluminum
Surgery
Neurectomy (nerving): severing of the palmar digital nerves on either side of the deep flexor
Gallium Nitrate ???
– Many times bone disorders are caused
by an excess of Aluminum
– Gallium competes with Aluminum for
absorption in the bone, causing a delay in
further degeneration
– Fed as a supplement
Gallium nitrate is not fully accepted as helpful for navicular horses.