NAVICULAR SYNDROME AND HEEL PAIN IN
THE PERFORMANCE HORSE
Phillip D Jones, DVM, MS
Diplomate American College of Veterinary Surgeons
OUTLINE
• Causes for caudal heel pain
• Diagnostics and therapies
• Shoeing recommendations
CAUDAL HEEL PAIN
• Navicular syndrome
• Degenerative process that changes the bone-initiation
and progression of the disease is a result of
excessive and prolonged forces of compression on
the bone
• Important factors- signalment, conformation, and use
NAVICULAR SYNDROME
• Mild to moderate intermittent lameness
• Insidious onset
• Perceived as shoulder lameness
• Poor confirmation
• Bilateral lameness
• Lameness switches to contralateral limb after unilateral
PD block
NAVICULAR SYNDROME
• Important PE findings
-contracted heels
-atrophied frog
-small foot compared with body size
NAVICULAR SYNDROME
• Medical therapy
-shoeing changes
-anti-inflammatory medications
-rest
• Surgical therapy- PD neurectomy (criteria! &
complications!)
DIAGNOSTICS
• Localization
• Palmar Digital Nerve block
-Mepivacaine: 1 -1.5ml /nerve
DIAGNOSTICS
NAVICULAR SYNDROME
• Changes within the navicular bone
-edema
-vascular stasis
-enlargement of the nutrient foraminae
-cyst-like medullary areas
-subchondral bone changes
-changes in the flexor surface
-fragmentation of the distal border
ADD NORMAL NB
Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008
SHOEING
• Correct or preserve dorsopalmar and lateromedial foot balance
• Hoof pastern angle should be straight
• Foot trimmed to maintain heel mass and shorten toe to facilitate
breakover
• Elevation of heel may relieve pressure from DDFT on palmar
aspect of navicular bone
• Egg bar shoe: greater surface area disperses forces.
-Of 55 horses with navicular disease 53% had
permanent pain relief of lameness after egg bar
shoes in 12-40 month follow up.
SHOEING
• Key points:
• Correct and maintain dorsopalmar and lateromedial
balance
• Ease breakover
• Maintain heel mass
• Protect palmar aspect of the hoof from concussion
MEDICAL THERAPIES
• Intra-articular injection
• Intra-bursal injection
• Tilduronic acid (Tildren)
• NSAID’s
• Isoxuprine
-2.2% oral bioavailability
TREATMENT
CAUDAL HEEL PAIN
• Desmititis of the collateral ligaments.
• Tendonitis of the DDFT at 3 possible locations:
-insertion
-palmar to the navicular bone
-proximal to the navicular bone
• Desmitis of the impar ligament.
• Desmitis of the distal annular ligament.
• Synovitis in the distal interphaleangeal joint.
• Synovitis in the navicular bursa.
• Cystic lesion in the second phalanx
TREATMENT
SHOCKWAVE
• Extracorporeal shock wave
-generates a pulse wave within the body
• Encourages growth mediators and other cytokines
integral to the healing process
• Offers temporary pain relief
FRACTURE
Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008
BIPARTITE NAVICULAR BONE
• Develops as 2 separate centers of ossification that never unite
• Unilateral or bilateral
• Broad well defined lucent line between the 2 pieces
• Horse may be clinically normal, or have episodic lameness in
full athletic function
• No history of acute lameness as in fracture
BIPARTITE
Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008
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