26 DEPARTMENT OF AGRICULTURE. 



progress of the malady in town dairies, and the rapid destruction of herds in open fields, 

 can for a moment believe in the usual aggravation of the malady by bad stabling. Where 

 the malady has been induced among young stock by large dairymen to prevent subsequent 

 inconveniences, when the animals are fit to breed and yield milk, it has been found that 

 most survived when kept warm in close sheds. Recommendations as to ventilating sta 

 bles after disease had commenced have at times resulted in a much more rapid destruc 

 tion of the cattle, and we are bound to admit that a priori reasoning has often been at 

 fault on this subject. 



ABUNDANT MILK SECRETION. 



The universal prevalence of the lung plague in town dairies, where cows are kept for 

 an abundant production of milk, has led to the theory that the drain on the system thus 

 kept up induces the pleuropneumonia. It is asserted, and there appears to be some ground 

 for the belief, that the human female, as well as the female among lower animals, is more 

 susceptible to the influences of contagion than the male, but so far no facts of importance 

 have ever been published indicating that an abundant secretion of milk induces specific 

 disease and malignant fevers. Delafond has referred to abundant production in dairies 

 where pleuropneumonia was always troublesome, and expresses himself as follows: &quot;I 

 firmly believe that cows which calve every ten or eleven months, and which are constantly 

 yielding an abundant milk secretion, whether by being fed abundantly on rich provender, 

 or placing them in hot, damp stables, so as to check cutaneous and pulmonary secretion, 

 soon have their chest enfeebled, and are seized with pleuropneumonia; or, at all events, 

 and that is incontestable, they become predisposed to the disease, which they easily get on 

 being exposed to the breathing of a cold air, or to cold on the surface of the skin.&quot; 



Here, again, it is not difficult to trace the real effects of an abundant milk secretion 

 in stables that are close and ill-drained. Up to the time when the lung disease first 

 appeared in London it was not uncommon for cows to be milked for several consecutive 

 years. Large milkers were always kept on, and had a calf annually until too old or killed 

 by disease. The disease that killed them was not pleuropneumonia, but tuberculosis. That 

 malady, once so prevalent, is almost unknown now, inasmuch as the London cow feeders 

 have ceased to breed from their cows, and the average duration of a cow s lifetime in a 

 London shed docs not exceed six months. 



DRINKING COLD OR IMPURE WATP:R. 



It is hardly necessary to refer at length to this reputed cause of pleuroneumonia. Not 

 only is there an absence of fact in support of .the production of the malady by cold water 

 in winter and stagnant water in summer, but it is well known that the malady is usually 

 most rife in many cities during the summer, when cattle are allowed to roam at pleasure 

 during the day, coming in contact, and, therefore, infecting each other, while the supply 

 of water is good, and indeed unexceptionable. Were it worth while, I could easily 

 furnish many facts under this head indicating that there is no relation whatever be 

 tween the condition and quantity of water cattle drink and the development of the lung 

 disease. 



