348 DISEASES OF HORSES AND CATTLE 



sometimes introduced by milch heifers. It is con- 

 sidered that the disease is peculiar to the milch 

 cow, that it occurs primarily while the animal is in 

 that condition, and that it is casually propagated 

 to others by the hands of the milkers. But consid- 

 ering the general mildness of the disease, the fact 

 of its being at times in some individuals entirely 

 overlooked and that its topical severity depends 

 almost wholly on the rude tractions of milking, it 

 would perhaps be going too far to assert its in- 

 variable and exclusive origin, under circumstances 

 just mentioned, yet I have frequently witnessed 

 the fact that stirks, dry heifers, dry cows milked 

 by other hands, grazing in the same pasture, feed- 

 ing in the same sheds, and in contiguous stalls, re- 

 main exempt from the disease. Many intelligent 

 dairymen believe that it occurs more frequently 

 as a primary disease among milch heifers, but I 

 have not been able to confirm this remark by my 

 own observation. It does not appear to be Jess 

 frequent on hills than in the vale. It has been 

 seen primarily on the stall-fed as well as on the 

 grazing animals. 



Origin of the disease: I have met with several 

 intelligent dairymen whose relatives had some 

 good reason to ascribe its occurrence to the con- 

 tagion of the equine vesicle communicated by the 

 hands of the attendants of both animals, but very 

 little of this disease has been noticed of late years, 

 although I know of several farriers who have 

 been affected from the horse and resisted subse- 

 quent variolation or vaccination, and I have seev * 



