350 DISEASES OF THE HORSE'S FOOT 



explored with the probe and a knowledge of its exact 

 dimensions arrived at. This is carefully noted, and the 

 horn of the wall for some little distance around it then 

 rasped down quite thin. Immediately over the sinus, and 

 for a short distance on either side of it, the horn is stripped 

 away to the sensitive structures. The cavity of the fistula 

 is then opened up with a scalpel, and every particle of 

 diseased tissue removed with this instrument and a pair 

 of forceps. After-dressing consists simply in the application 

 of suitable antiseptics. 



When the Complication of Necrosed Tendon or Ligament 

 exists. — We may take it as an axiom that wherever this 

 exists, whether it is in the extensor pedis, in the lateral 

 ligaments of the joint, or in portions of the flexor, all 

 diseased structures should, where possible, be removed. This 

 is done either with a scalpel or with a curette. 



When septic matter has gained the sheath of the perforans, 

 and the formation of pus therein is indicated by inflam- 

 matory swellings in the hollow of the heel, it is sometimes 

 advisable to lay the sheath open for 1 to 2 inches along the 

 course of the tendons. This, if a fistula is present, may be 

 best done with a blunt-pointed bistoury, or with a cannulated 

 director and a scalpel. With the pus thus given exit, and 

 an antiseptic dressing regularly applied, the case sometimes 

 ends in rapid resolution. More often than not, however, it 

 is found that the pus has been liberated too late, and that 

 it has gravitated in the sheath to the extent of affecting the 

 plantar aponeurosis. Or it may be, of course, that it was in 

 the plantar aponeurosis the disease commenced. Whichever 

 may have been the case, we have in the hollow of the heel 

 one or more fistulous openings, or an opening we have made 

 ourselves, leading down to a necrosed portion of the terminal 

 expansion of the perforans. 



In such cases we ourselves have derived benefit from a 

 regular flushing of the sinuses with a 1 in 2,000 solution 

 of perchloride of mercury, introduced by means of a glass 

 syringe, followed later by flushing in the same manner with 

 a 1 in 40 solution of carbolic acid, the hollow of the heel 



