DISEASES OF THE HOKSE. 405 



inches from the heel. The same sloping- shape is to be observed in 

 cutting downward toward the bottom of the foot, at which point the 

 wall is to retain its normal thickness. The foot is now blistered all 

 around the coronet with Spanish-fl}^ ointment; when this is well set, 

 the patient is to be turned to pasture in a damp field or meadow. The 

 blister should be repeated in three or four weeks, and, as a rule, the 

 patient can be returned to work in two or three months' time. 



The object of the tip is to throw the weight on the frog and heels, 

 which are readily spread after the horn has been cut away on the sides 

 of the wall. The internal structures of the foot at the heels, being 

 relieved of excessive pressure, regain their normal condition if the 

 disease is not of too long standing. The blister tends to relieve any 

 inflammation which maj^ be present, and stimulates a rapid growth of 

 health}^ horn, which, in most cases, ultimately forms a wide and nor- 

 mal heel. In old, chronic cases, with a shrunken frog and increased 

 concavity of the sole, accompanied b}^ excessive wasting of all the 

 internal tissues of the foot, satisfactory results can not be expected 

 and are rarely secured. Still, much relief, if not an entire cure, may 

 be effected by these measures. 



When thrush is present as a complication, its cure must be sought 

 by measures, directed under that heading. If sidebones, ringbones, 

 navicular disease, contracted tendons, or other diseases have been the 

 cause of contracted heels, treatment will be useless until the cause is 

 removed. 



SAND-CRACKS. 



A sand-crack is a fissure in the horn of the wall of the foot. These 

 fissures are quite narrow, and, as a general rule, they follow the 

 direction of the hornj' fibers. They may occur on any pai-t of the 

 wall, but ordinarily are onl}' seen directlv in front, when they are 

 called toe-cracks; or on the lateral parts of the v^'alls, w^hon they are 

 known as quarter-cracks. (Plate XXXIII.) 



Toe-cracks are most common in the hind feet, vv'hile quarter-cracks 

 nearl}^ alwaj's affect the fore feet. The inside quarter is more liable 

 to the injury than the outside, for the reason that this quarter is not 

 only the thinner, but during locomotion receives a greater part of the 

 weight of the bod3\ A sand-crack may be superficial, involving only 

 the outer parts of the wall, or it maj'' be deep, involving the whole 

 thickness of the wall and the soft tissues beneath. 



The toe-crack is most likely to be complete — that is, extending from 

 the coronary band to the sole — while the quarter-crack is nearly always 

 incomplete, at least when of comparatively recent origin. Sand-cracks 

 are most serious when they involve the coronary band in the injury. 

 The}" may be complicated at any time b}^ hemorrhage, inflammation of 

 the laminffi, suppuration, gangrene of the lateral cartilage and of the 



