SAND-CKACKS. 407 



horn on the borders of the fissure loses its vitality and scales otf, 

 sometimes through the greater part of its thickness, leaving behind 

 a rough and irregular channel extending from the coronet to the end 

 of the toe. 



In man}^ cases of quarter-crack, and in some cases of toe-crack as 

 well, if the edges remain close together, with but little motion, the 

 fissure is dry; but in other cases a thin, offensive discharge issues 

 from the crack and the ulcerated soft tissues, or a funguslike growth 

 protrudes from the narrow opening. 



When the cracks are deep, and the motion of their edges consider- 

 able, so that the soft tissues are bruised and pinched with every move- 

 ment, a constant inflammation of the parts is maintained and the 

 lameness is severe. 



Ordinarily the lameness of sand-crack is slight when the patient 

 walks; but it is greatly aggravated when he is made to trot, and the 

 harder the road the Avorse he limps. Furthermore, the lameness is 

 greater going down hill than up, for the reason that these conditions 

 are favorable to an increased motion in the edges of the fissure. 

 Lastly, more or less hemorrhage accompanies the inception of a sand- 

 crack when the whole thickness of the wall is involved. Subsequent 

 hemorrhages may also take place from fast work, jumping, or a 

 misstep. 



Treatment. — In so far as preventive measures are concerned, but 

 little can be done. The suppleness of the horn is to be maintained by 

 the use of ointments, damp floor, bedding, etc. The shoe is to be pro- 

 portioned to the weight and work of the animal; the nails holding 

 it in place are to be of proper size, and not driven too near the heels ; 

 sufficient calks and toe-pieces must be added to the shoes of horses 

 working on slippery roads; and the evils of jumping, fast driving, 

 etc., are to be avoided. 



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 prominent maker of 

 veterinary instruments. (Plate XXXIII.) These instruments com- 

 prise 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 2 parts of gutta-percha and 1 pan 



