1092 DISEASES OF THE FOOT. 



and the softer the material produced, the graver the case. The more 

 extensive the disease and t lie greater the tendency to spread, the less the 

 chance of recovery. Treatment is particularly difficult when the 

 lamina' arc attacked, easier when the condition is confined to the 

 frog and sole. Rapid extension is always an unfavourable sign. 

 The most difficult cases are those in which a predisposition to the 

 disease exists, as shown by several feet being affected. 



Treatment. Perhaps in no other disease have so many drugs been 

 tried as in canker. The selection of a proper remedy certainly plays 

 a very important part in treatment, and only ranks second to the 

 maimer of applying it. Caustics, which destroy the excessive growths, 

 together with astringents and disinfectants, appear most effective. 

 Sublimate, chloride of zinc, carbolic acid, calomel, salicylic acid, 

 camphor, iodine, and many others have in turn found supporters, 

 but, as Haubner very truly said, there is no specific against canker. 



In addition to local disinfection, it is necessary, firstly, to destroy 

 the new growths on the papillae ; and, secondly, to check proliferation 

 in the reticular tissue. Success in the first case depends on the size 

 of the new growths. Caustics, the actual cautery, or the knife may 

 be employed ; but, whatever the means selected, care must be taken 

 to remove all diseased tissue. The hoof must be thoroughly thinned, 

 every particle of undermined horn removed for a distance of ^ an 

 inch round the diseased area, the margins of which are easily recognised 

 by the fact that the horn there is adherent to the sensitive membrane 

 beneath. By using an Esmarch's bandage, bleeding may be entirely 

 avoided, and the seat of operation kept continuously under observation. 

 All fragments of diseased tissue should be removed with the knife 

 or curette. This treatment has proved more successful than the 

 use of caustics. Healthy tissue should naturally be spared, but 

 not at the expense of leaving disease behind. The softness and 

 yellow colour of the altered tissues enable them readily to be distin- 

 guished. The operation is concluded by applying a pressure dressing 

 saturated with weak formalin solution. As considerable pain attends 

 the above manipulation, chloroform or a large dose of morphine 

 should be given. Next day the dressing is removed. The field of 

 operation will then be found covered with a cheesy adherent material, 

 which must be removed with the knife or curette, but without wounding 

 the sensitive structures beneath. The parts are then redressed with 

 dilute formalin or whatever agent has been chosen, and packed 

 with wads of tow under a pressure bandage. 



Amongst caustics, nitrate of lead, recommended by Piitz, perhaps 

 stands first. When strewed over the diseased surface in the form of 



