LAMENESS, FROM VAiciOU* tfAOSES. 356 



The cause of toe sand-crack 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, 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 certainly, 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- 

 crack, 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 its secretory apparatus, 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 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 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 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 

 of 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 



