Page 279 - The Veterinary Care of the Horse

toe can be used to bring the breakover back from the toe and reduce the stress on the

dorsal hoof wall.
VetBooks.ir • Once the infection has resolved and the laminae are dry, the hoof wall defect may be

repaired with an acrylic material. However, it is best to leave the resected area open if
possible as the disease may recur under the repair. If the lesion is not too extensive, the

horse can recommence work at this stage although the exercise programme may have to
be modified.

• The defect will gradually grow out. A brush is used to keep the area clean.
• Hoof-wall growth may be improved in some cases by dietary supplements.

• The feet should be kept as clean and dry as possible while the lesion grows out. Ideally

affected horses should not be worked or turned out in wet, muddy conditions.

Prognosis

Recurrence is common unless the underlying factors are adequately dealt with. Some horses
experience repeat episodes despite good hoof care. The corrective hoof trimming can take
many months. Excellent management is required while the hoof defect is growing out.

NAVICULAR SYNDROME

Navicular syndrome is a progressive, degenerative disease involving the navicular bone, its
supporting ligaments, the navicular bursa and the deep digital flexor tendon (DDFT). It may

affect one front foot, or more commonly both front feet, and occasionally occurs in the hind
feet of horses. It rarely affects ponies. The lameness is due to pain from the heel region of the

foot. The average age of onset is 7–9 years.

Anatomy

The distal interphalangeal (DIP), or coffin, joint is formed from the articular surfaces of the
pedal bone, the distal end of the middle phalanx and the navicular bone. The DDFT passes

over the palmar (back) surface of the navicular bone which is covered with fibrocartilage and
attaches to the pedal bone. A fluid-filled sac, the navicular bursa, cushions the movement of
the DDFT over the navicular bone (see Figure 6.4).

The navicular bone has several supporting ligaments, collectively known as the navicular
suspensory apparatus. These include: