Page 196 - The Veterinary Care of the Horse

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Figure 6.2a and b Ground surface of a front foot

When the horse stands on a hard surface, its weight is taken by the hoof wall and the
outer rim of the sole. However, the weight is not evenly distributed around the hoof wall.
Most is taken by the heels and at the junction between the toe and the quarter on either side

of the hoof. In an unshod horse, the bars and the frog may also take some of the weight. On a
soft surface, the sole helps to support the horse’s weight.

The internal surface of the hoof wall has approximately 600 horny or insensitive

laminae. These interdigitate with the sensitive laminae on the surface of the pedal bone.
This interlinking of the sensitive and insensitive laminae holds the pedal bone firmly in

position.

Hoof growth

The hoof wall grows down from the coronary band at the rate of 6–10 mm ( in) a
month. It grows fastest at the toe. It takes approximately 6 months for the horn produced at

the coronet to reach the ground at the heels and 9–12 months to reach the toe.

Hoof rings

The wall is normally smooth, but variation of growth rate due to diseases such as laminitis

and dietary changes can cause horizontal rings to develop on the surface of the hoof (Figure
6.3).