k;ne:b, FBTi^ocK, anklb, and foot. 217 



When a fissure has made its appearance, means are to be adopted 

 which will prevent it from growing longer or deeper; and this can only 

 be done by arresting all motion in the edges. The best and simplest 

 artificial appliance for holding the borders of a toe-crack together is the 

 Vachette clasp. These clasps, and the instruments necessary for their 

 application, can be had of any of the more prominent makers of veterin- 

 ary instruments. These instruments comprise a cautery iron with which 

 two notches are burned in the wall, one on each side of the crack, and 

 forceps with which the clasps are closed into place in the bottom of the 

 notches and the edges of the fissure brought close together. The clasps 

 being made of stiff steel wire are strong enough to prevent all motion in 

 the borders of the crack. Before these clasps are applied the fissure 

 should be thoroughly cleansed and dried, and, if the injury is of recent 

 origin, the crack may be filled with a putty made of two parts of gutta 

 percha and one part of gum ammoniac. The number of clasps to be used 

 is to be determined by the length of the crack, the amount of motion to 

 be arrested, etc. Generally the clasps are from one-half to three-quar- 

 ters of an inch apart. The clasps answer equally as well in quarter- 

 crack if the wall is sufficiently thick and not too dry and brittle to with- 

 stand the stain. 



In the absence of these instruments and clasps a hole ma3' be drilled 

 through the horn across the fissure, and the crack closed with a thin 

 nail made of tough iron, neatly clinched at both ends. A plate of steel 

 or brass is sometimes fitted to the parts and fastened on with short 

 screws; while this appliance may prevent much gaping of the fissure, 

 it does not entirely arrest motion of the edges for the simple reason that 

 the plate and screw cannot be rendered immobile. 



In all cases of sand-crack the growth of horn should be stimulated by 

 blistering the coronary band. In simple quarter-crack recovery will 

 often take place if the coronet is blistered, the foot shod with a "tip," 

 and the patient turned to pasture. 



The shoe, in toe-crack, should have a clip on each side of the fissure 

 and should be thicker at the toe than at the heels. The foot should be 

 lowered at the heels by paring, and spared at the toe, except directly 

 under the fissure where it is to be pared away until it sets free from the 

 shoe. 



Navicular Disease. Navicular disease, often called "navicular 

 arthritis" by the English, is an inflammation of the sesamoid sheath, in- 

 duced by repeated bruising or laceration, and complicated in many cases 



