170 DISEASES OF THE HORSE’S FOOT 
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 imme- 
diately above it will have the desired effect. An increased 
secretion of horn is brought about, and by this simple 
