62 Management and Treatment of the Horse. 



There is no process of incubation in this affec- 

 tion. If all the conditions are favourable to 

 radiation, the system can contract the infection 

 suddenly, and become affected to a degree en- 

 titling it to the term of influenza in five minutes ; 

 but if the conditions are not so favourable, it will 

 require twenty or thirty minutes' exposure to the 

 same trying circumstances to produce the same 

 effect, and in some less susceptible animals they 

 may tolerate the same influence for several days 

 before becoming affected. I am decidedly of 

 opinion that some horses are not susceptible to 

 its influence, and even those that are, after they 

 have passed through it, with very rare exceptions, 

 enjoy an immunity from it. It would appear that 

 the constitution had become inured or accommo- 

 dated to it, for they enjoy perfect health after, 

 and this, too, in the same atmosphere. Horses 

 occupying the most healthy and best ventilated 

 stables are equally liable to contract the com- 

 plaint, but there is this difference, it is less 

 malignant and less fatal. It is a fact that at 

 other times the animals may experience a chill, 

 and have a check of perspiration, and the result 

 will be an ordinary catarrhal affection. But 

 when this subtle agency exists in the air and is 

 exerting itself, another phenomenon is witnessed 

 of an entirely different nature, and of essentially 

 typhoid tendencies, the distinguishing mark or 

 effect of which is an unusual, peculiar, and 

 general weakness, a most susceptible system, and 

 the small, feeble character of the pulse. 



Is influenza contagious and infectious ? My 



