the
opposite side concave. Fig. 85, showing the foot in section from side to
side, gives an exact idea of this malformation.

_Causes_.--As was the case with the condition previously described, this
abnormality finds its primary cause in an unequal distribution of weight
due to vice of conformation in the limb above, causing one side of the
hoof to be higher than the other. As a result of this, the wall that is
inordinately increasing in height commences to bulge outwardly (Fig. 85,
_a_), while the opposite (Fig. 85, _b_) becomes concave.

The same state of affairs may be occasioned in the forge by leaving one
side of the foot too high, and subjecting the other to excessive paring for
several consecutive shoeings.

_Treatment_.--In the main this condition may be regarded as a long-standing
and aggravated form of the foot with unequal sides. We may say at once,
therefore, that it is not so easily remedied as that simpler defect; that,
although identical principles will be followed in its treatment, cure must
be a matter of some considerable time.

[Illustration: FIG. 85.--SECTION THROUGH A CROOKED FOOT. _a_, The higher
and convex side of the wall; _b_, the lower and concave side of the wall]

Again, we must look to successive parings of the wall of the higher side to
bring about a gradual return to the normal. At the same time, the tendency
to contraction of that side is counteracted by shoeing wide, and, if
necessary, giving to the upper surface of that branch of the shoe what we
have termed elsewhere a 'reversed seating'--viz., an incline of its upper
surface from within outwards.

CHAPTER VII

DISEASES ARISING FROM FAULTY CONFORMATION

A. SAND-CRACK.

_Definition_.--A solution of continuity of the horn of the foot, occurring
usually in the wall, and following the direction of the horn fibres.

_Classification_.--It is usual to classify sand-cracks according to--

_(a) Their Position_.--_Toe-crack_ when occurring in the middle line of the
horn of the toe, and _quarter-crack_ when occurring in the horn of the
quarters.

Sand-crack of the frog and sand-crack of the sole may also each be met
with. They are, however, of rare occurrence, and are seldom serious enough
to merit special attention.

The toe-crack is met with more often in the hind-foot than in the fore,
while the quarter-crack more often than not makes its appearance in the
fore-foot, and is there, as a rule, confined to the inner side. Th