544 
LAMENESS IN HORSES. 
as London, are the sufferers from this disease. I say “ suf- 
ferers,” because it is only those veterinary surgeons whose 
practice lies among horses of this description that have any 
conception of the amount of pain and irritation to which sand- 
crack, simple as it may seem to those who are in the habit of 
meeting with quarter sandcrack only, on occasions is found to 
give rise. 
The Cause of Toe Sandcrack is violence : shoeing, also, 
may have something to do in its production. The horses 
who are the subjects of it are those employed in laborious and 
straining draft. The toe of the hind foot is the grand fulcrum 
through which the hind limbs, the propellers of the body, exert 
their power; and it is in some violent and forcible effort that the 
hind hoof, strained as it is to its uttermost, and in particular at 
the toe, splits, commonly first at the coronet, the same as in the 
fore foot, where the horn, but newly formed, is thin and unresist- 
ing, the crack subsequently extending gradually down the wall, 
even as far as the point of the toe. Digging the tip of the toe 
into the ground, or stamping it hard down upon the pavement, 
and especially when this stress upon the fore part of the wall is at 
all times promoted by high caulkingsto the shoe, must certainly, 
one would think, be the main producer of toe sandcrack ; an 
opinion still farther favoured by the observation which has been 
made of shaft horses in drays being more subject to the acci- 
dent than trace horses. Still, however, for all this, it behoves 
me to say, that with the best judges of such matters, the point 
is one not yet set free from doubt and difference of thinking. 
Short and upright pasterns, with clubby prominent hoofs, in- 
dicate a predisposition to toe sandcrack, the disease being in no 
instances seen in flat, shelvy, oblique hoofs. It is said, sand- 
crack may originate in tread. Undoubtedly, any lesion of the 
coronary body sufficient to injure or destroy its secretory ap- 
paratus may occasion imperfect or morbid formation of horn, or 
loss of horn altogether ; but I do not believe this to be a very 
common cause of sandcrack. 
The Consequences of Sandcrack in the Hind Hoof 
are, as I have before hinted at, apt to be of a much more serious 
nature than any usually arising from a quarter sandcrack. 
Whether the crack extend to the bottom of the wall or not, 
being uniformly of the penetrant description, lameness to 
greater or less degree is the invariable result. And when the 
fissure does reach down to the toe, the wall opens and exposes 
the laminae, probably the whole way from the coronet down- 
ward, the consequence of which is inflammation and suppura- 
tion of those parts, and sometimes even mortification and 
sloughing of them ; and not of them alone, but of the bone to 
