CHAPTER XII. 



miscellaneous minor operations. 



Operation for Hoof Cracks. 



INDICATIONS. — Hoof-cracks or sand-cracks, as they 

 are usually called, are classified according to position into 

 toe-cracks when located anteriorly and quarter-cracks when 

 situated in the quarters. They are complicated or uncompli- 

 cated according to whether or not they extend into the sensi- 

 tive laminae or the coronary cushion. 



Natural thinness of the wall, brittleness of the horn, 

 contraction of the hoof, dropping of the sole (pumice foot) 

 and certain definite conformations are so many predisposing 

 states which leave the wall susceptible to fracture under 

 the influence of more or less violence in the form" of severe 

 traction or hard pounding. There are, however, numerous 

 toe-cracks, especially in the hind feet of draft horses, that 

 develop in the absence of any perceptible predisposing in- 

 fluence, apparently from sheer violence. Predisposition, as 

 a cause of hoof-cracks, is more influential in quarter-cracks 

 than in fractures at the toe. The most formidable hoof- 

 cracks, however, although not the most common, are those 

 caused -by a diminished production of horn at an isolated 

 spot on the coronary cushion, due to previous disease or in- 

 jury. The tread of a sharp calk, a necrotic inflammation, 

 a quittor or any wound that destroys a part or all of the 

 coronet at a definite spot, often results in the outgrowth of 

 a "through and through" seam, because the production of 

 horn from the injured point does not keep pace with the 

 growth from the parts immediately adjacent. This variety 

 of hoof cracks is either incurable or else will yield only to a 

 special treatment hereafter mentioned. (See after-care.) 



As regards surgical treatment, hoof-cracks should be 

 divided into two classes, viz.; — (i) Those in hoofs having 

 an integral coronary cushion, and (2), Those in hoofs whose 

 coronary cushion possesses a local defect. The former will 

 yield to treatment, whilst the latter, owing to a serious loss 

 of coronary substance, may be incurable. In the selection 

 of cases for operation the condition of the coronet is, there- 



423 



