324 TREATMENT OF LAMENESS. 



liend there is not much truth in either of these suppositions. It 

 is a much more severe irritant than a blister, and often removes 

 pain very rapidly when repeated blisters have failed to do so. 

 In bone diseases, and in all causes of chronic lameness, it is of 

 great benefit, and seems to act by powerfully exciting the heal- 

 ing process in the part diseased. 



The firing may be in lines, and superficial, the transverse 

 method being the least calculated to blemisli ; or it may be in 

 points, and deep, by pyro-puncture (see drawing of instrument, 

 rig. 24, page 159), and into the diseased structure. This 

 latter method is the more easily performed, and the more 

 effective. 



Nothing is more calculated to dispel the idea of the correct- 

 ness of the cou7iter-irritSitioii theory than the dissection of a 

 part which has been recently fired (say three days after tlie 

 operation), when it will be found that the skin, subcutaneous 

 tissue, and the bones — when they are superficially situated, such 

 as those of the hock, pastern, &c. — are involved in the inflam- 

 matory action so induced. Thus a bone-spavin lameness is 

 removed by the inflammation excited by the cautery in the 

 diseased bones, providing a supply of material for the purpose 

 of uniting them together into one immoveable mass ; or, as in 

 caries of a ginglymoid joint, for the repair of destroyed structure, 

 as already explained. 



Setons act very satisfactorily in some cases of bone diseases, 

 especially in those accompanied by external heat of the part ; 

 they produce a discharge of pus, and their action can be con- 

 tinued for a much longer time than that of blistering or firing. 

 In tendinous or ligamentous lamenesses, with much thickening 

 of the integuments and subcutaneous structures, setons should 

 not be employed, as they leave much additional thickening, and 

 are not so effectual as the actual cautery. 



