LAMENESS, FROM VaarUUs UAOSES. 3b 
The cause of toe sand-crack is violence. Shoeing, also, inay 
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 
ag it is to its uttermost, and in particular at the toe, splits, com. 
monly first at the coronet, the same as in the fore-foot, where the 
horn, but newly-formed, is then unresisting, the crack subse: 
quently 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 forepart of the wall is at all times promoted 
by high caulkings to the shoe, must certamly, one would think, 
be the main producer of toe sand-crack—an opinion still further 
favored by the observation which has been made of shaft-horses 
in drays being more subject to the accident than trace-horses, 
Still, however, for all this, it behooves 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, indicate a predisposition to toe sand- 
vrack, the disease being in no instances seen in flat, shelvy, ob- 
lique hoofs. It is said sand-crack may originate in tread. Un- 
doubtedly any lesion of the coronary body, sufficient to injure or 
destroy ifs secretory apparatus, may occasion imperfect or morbid 
formation of horn, or loss of horn altogether; but I do not believe 
Lhis to be a very common cause of sand-crack. 
The consequences of sand-crack in the hind hoof are, as I have 
before hinted, apt to be of a much more serious nature than any 
usually arising from a quarter sand-crack. Whether the crack 
extend te 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 lamina, probably the whole 
way from the coronet downward, the consequence of which is in- 
flammation and suppuration of those parts, and sometimes even 
mortification and sloughing of them; and not of them alone, but 
ef the bone to which they are attached as well, which not unfre- 
quently runs into a state of caries, ending in defalcation of sub- 
stance, to be filled up by the effusion of callus, which usually 
