SAND-CRACKS. 405 



and lower surfaces flat. This tip is to be fastened on with six or eight 

 small nails, all set well forward, two being in the toe. With a com- 

 mon foot rasp begin at the heels, close to the coronet, and cut away 

 the horn of the wall until onlj- a thin layer covers the soft tissues 

 beneath. Cut forward until the new surface meets the old 2| or 3 

 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-fly 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 

 l^atient 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 wdiich may be present, and stimulates a rapid growth of 

 healthy 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 by 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. 



"VVlien 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 direc- 

 tion of the horny fibers. They may occur on any part of the wall, but 

 ordinarily are only seen directly in front, when they are called toe- 

 cracks; or on the lateral parts of the walls, when they are known as 

 quarter-cracks. (Plate XXXI.) 



Toe-cracks are most common in the hind feet, while quarter-cracks 

 nearly always 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 body. A sand-crack may be superficial, involving only 

 the outer parts of the wall, or it may 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 



