28 VETEETNAEY HYGIENE 



DISEASES PRODUCED BY IMPURE WATER. 



In spite of the immense amount of research which has 

 been applied to the question of water and disease, it is 

 remarkable what a very unsatisfactory condition the matter 

 is still in. 



The human hygienist can only place his finger on two 

 diseases communicable by water, viz., cholera and enteric, 

 and nearly all the observations which have been made in 

 connection with water and disease bear on these two specific 

 infections. 



Nobody supposes that either of these diseases originate 

 in water, but that the organisms gain access to it and are 

 thus distributed. The same results would follow if scarlet 

 fever, small-pox, diphtheria and typhus were associated 

 with diarrhoea or bowel trouble, and through defective 

 drainage found their way into the drinking-water; this 

 would then become the chief medium for their distribution, 

 whereas, of course, it is not so. 



Neither cholera nor enteric affect the lower animals, but 

 if we take the specific diseases which are peculiar to them, 

 there is no difficulty in understanding that many of them 

 may be water-borne. 



Glanders, for example, can undoubtedly be conveyed by 

 the drinking-water, the affected animal has only to leave 

 behind in the trough or bucket some of the nasal discharge 

 in order to infect the first horse that swallows it. 



Swine fever may also spread through the water supply 

 being infected with the specific microbe. Foot and mouth 

 disease is probably commonly spread by this means, as the 

 sahva is most infective. Cattle plague which is associated 

 with acute diarrhoea will also be propagated in this way, 

 should the excreta contaminate the drinking supply, and 

 so, in fact, may any specific disease capable of infection 

 through the digestive canal. 



If, on the other hand, we are asked to indicate impurities 

 in water which produce disease it is really a very difficult 

 matter. It is easy to understand the production of dices- 



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