th
it.

A like favourable prognosis may be given in the case of cracks occasioned
by purely accidental causes.

Ordinarily, however, cracks once commenced tend rather to increase than
decrease in size and severity. From being superficial and incomplete, they
become complete and deep, with every unfavourable circumstance that an
increase in size and depth brings with it.

This much, however, may be promised to the owner. A simple crack, even
though originating from the coronary margin, is, in the vast majority of
cases, curable. Under a rational treatment its increase in size may be
prevented, and a sound wall caused to grow down from the coronet.

_Treatment_.--The principles governing the treatment of sand-crack are
simple enough in themselves, if not always followed by success.

1. _Preventive_.

This, as a rule, does not suggest itself until a crack of greater or less
extent has made its appearance. Then, simultaneously with the treatment
proper of the lesion, preventive measures should be adopted, to aid both in
the healing of the fissure already present, and to ward off the occurrence
of others that might be likely to form. The hoof, if abnormally brittle,
should be regularly dressed with a suitable ointment (one containing
glycerine for preference), and its horn kept as nearly as possible in
a normal condition. When the condition of the horn predisposing to its
fracture is brought about by excessive wet, then the appropriate preventive
measures to be adopted suggest themselves.

With regard to the lesion itself, we may term 'preventive treatment' all
those measures having for their object the prevention of increase in the
size of the crack. They are as follows:

_(a) Blistering the Coronet_.--In a simple case, where the crack is
superficial and close under the coronary margin of the wall, a sharp
cantharides blister to the coronet immediately above it will have the
desired effect. An increased secretion of horn is brought about, and by
this simple means the crack prevented from becoming longer. Very often this
is all that is necessary. In fact, we may say here that, no matter what
other treatment is adopted, the simultaneous application of a blister to
the coronet is always beneficial. To derive full advantages therefrom,
the blistering should be repeated several times at intervals of about a
fortnight.

_(b) Clamping the Crack_.--When the services of a skilled smith are at
hand, one of the readiest met