TREATMENT OF CANKER. 
817 
ranks second to the manner of applying it. Speaking generally, 
caustics, which destroy the excessive growths, together with astringents 
and disinfectants, appear most effective. Sublimate, chloride of zinc, 
carbolic acid, calomel, camphor, iodine, and many others have in turn 
found supporters, but, as Haubner very truly said, there is no specific 
against canker. That is entirely true, and it requires long and close 
observation to discover the right material in any given case. 
In addition to local disinfection, it is necessary, firstly, to destroy the 
new growths on the papillae ; and, secondly, to check proliferation and 
secretion in the rete 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, and the sole be reduced to a mere 
pellicle for a distance of £ an inch round the diseased area, the margins 
of which are easily recognised by the fact that the horn there becomes 
adherent to the sensitive structures beneath. By using an Esmarch’s 
bandage (see Dollar’s “Operative Technique,” p. 168), 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 yelfow colour of 
the altered tissues enable them readily to be distinguished. The opera¬ 
tion 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. Two or three 
days later 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 formalin or whatever 
dressing has been chosen. 
Amongst caustics, nitrate of lead, recommended by Putz, perhaps 
stands first. When strewed over the diseased surface in the form of 
powder, it forms a dry scab, checks extension of the growth, exerts an 
intense drying action, and checks proliferation and secretion in the rete 
tissue. Sometimes the process starts again under the dry crust, which 
therefore requires to be carefully examined during the next few days. 
Inorganic acids, particularly fuming nitric acid, can also be used, but 
their application is more difficult, whilst their action is certainly not more 
satisfactory than that of nitrate of lead. The recent experiments with 
sulphuric acid in the treatment of grease suggest the advisability of 
trying it in canker; on account of its caustic, antiseptic, and drying 
v.s. 8 o 
