The management and treatment of the horse in the stable, field, and ...

78 The Management and Treatment of the Horse,
healthy well-formed foot when the sole is placed upon
the ground the front exhibits an angle of forty-five,
differing, however, in many horses to the extent of the
angle ; still in a healthy foot it is about the fourth
part of a semicircle. When the crust has a greater
degree of obliquity it is said that the crust has " fallen
in," and when the sole is too flat, it is said to be
pumiced or convex. If the front be more upright
than the above angle it is a sure sign of a contracted
foot with the sole too concave. When the crust is
deep at the heel it is a foot liable to contraction,
thrush, sandcrack, and inflammation. The pastern
will be found too upright, and the horse have a very
unpleasant action. If, on the other hand, the crust
diminished too rapidly from front to back and the
heels are low, this is always accompanied by too great
obliquity of the pastern, producing a weakness in the
joint and liability to sprain the back sinew. The foot
itself will be weak and have a tendency to that hidden
conrplaint called navicular joint disease. The general
thickness of the crust in front is about half-an-inch,
becoming thinner at the quarters and heels. This
will show the necessity for shoeing-smiths being
adepts at driving nails, seeing the small space they
have to nail to. The crust is thinner and a little
higher up on the inside than on the outside quarters.
This is another wise provision of Nature, because being
placed under the inner splint bone more of its weight
rests upon the inside than the outside, consequently
it is enabled to expand more, and thus, by its elasti-
city, assists in lessening the force of concussion. The