Page 198 - The Veterinary Care of the Horse

thickness of the hoof wall and indicates the position of the sensitive tissues which lie

immediately inside it.
VetBooks.ir THE FROG

The frog is a triangular pad of soft, elastic horn which has a central cleft and deeper clefts on

each side. In the unshod horse standing on a firm surface it may or may not contact the
ground and support some of the horse’s weight, depending on the conformation of the sole. It
does help to support the weight of horses working on soft surfaces.

The frog and sole are composed of horn which is softer than that of the wall and

constantly flakes away. Any ragged pieces of frog should be trimmed to prevent them
trapping dirt and harbouring bacteria.

Internal structures

The internal structures of the foot (Figure 6.4) include the:
• pedal bone

• navicular bone

• distal end of the second phalanx

• coffin joint
• navicular bursa

• cartilages of the foot

• insertions of the deep digital flexor tendon and the common digital extensor tendon

• digital cushion

• sensitive laminae
• ligaments, blood vessels and nerves.