592 VETEEINAEY HYGIENE 



but as the operation is harmless, and fully believed in by- 

 many in the profession and the majority of laymen, there 

 is no reason why its practice should not be continued. 



Other measures of protection which suggest themselves 

 are improvement in the land by draining and crop grow- 

 ing; draining should prove particularly useful, and the 

 remarks previously made on this subject may be consulted 

 with advantage. It has been clearly proved that in many 

 black-quarter districts improved methods of farming have 

 been followed by the almost entire obliteration of the 

 disease. 



The avoidance of affected pastures is an obvious precau- 

 tion not always practicable ; but it might be possible, as 

 suggested by Kitt, to prevent young animals in process 

 of shedding their teeth, or others with wounds on the limbs, 

 having access to pastures notoriously affected. Even the 

 precaution of preventing grazing and converting the grass 

 into hay may not be successful, as exclusively stall fed 

 cattle in Baden and Wiirtemberg are not infrequently 

 affected.* 



Protective inoculation has been largely practised on the 

 Continent of Europe with undoubted benefit, but no matter 

 what care is taken, a certain mortality, which is sometimes 

 alarming, must be expected from the operation. 



McFadyean recommends that individual owners should 

 be informed that the mortality from inoculation may 

 vary from | to 10 per cent. He attributes the mortality 

 which sometimes follows black quarter and anthrax in- 

 oculations to the differences in individual susceptibility, 

 which varies within rather wide limits ; so that a vaccine 

 perfectly safe for some, may prove too strong for others 

 where the powers of resistance are below the normal.f 



The protective substance is obtained from the disease 



while others close at hand are quite healthy, and even on the same 

 farm the disease may be confined to certain fields (McFadyean, 

 Journal of Comparative Pathology, vol. xv., part iv., 1902). 



* ' Veteriaary Pathology ': Friedberger and Frohner. 



f Journal of Comparative Pathology, vol. xv., part iv., 1902. 



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