1^2 THK HORSE. 



In 1766 it first attacked the horses in North America, but is not des- 

 cribed as again occurring in a severe form until 1 870-1 872, when it 

 spread over the entire country, from Canada south to Ohio, and then 

 eastward to the Atlantic and westward to California. It is now a per- 

 manent disease in our large cities, selecting for the continuance of its 

 virulence young or especially susceptible horses which pass through 

 the large and ill-ventilated and uncleaned dealers' stables and assumes, 

 from time to time an enzootic form, as from some reason its viru- 

 lence increases, or as from reasons of rural economy and commerce 

 large numbers of young and more susceptible animals are exposed to its 

 contagion. 



As one attack is self -protective, numbers of old horses, having had an 

 earlier attack, are not capable of contracting it again; but, aside from 

 this, young horses, especially those about four or five years of age, are 

 much more predisposed to be attacked, while the older ones, even if 

 they have not had the disease, are less liable to it. Again, the former 

 age is that in which the horse is brought from the farm where it has 

 been free from the risk of contamination, and is sold to pass through 

 the stables of the country taverns, the dirty, infected railway cars, and 

 tUe foul stockyards and damp dealers' stables of our large cities. 

 Want of training is a predisposing cause. O.erfed, fat young horses, 

 which have just come through the sales' stables, are much more sus- 

 ceptible to contagion than the same horses are after a few months of 

 steady woik. 



The atmosphere is the most common carrier of the infection from sick 

 animals to healthy ones, and through it it may be carried for a consider- 

 able distance. The contagion will remain in the straw bedding and 

 droppings of the animal, and in the feed in an infected stable, for a con- 

 siderable time, and if these are removed to other localities it may be 

 carried in them. It may be carried in the clothing of those who have 

 been in attendance on horses suffering from the disease. The drinking 

 water in troughs and even running water may hold the virus and be a 

 means of its communication to other animals even at a distance. Brick 

 walls, old woodwork, and the dirt which is too frequently left about the 

 feed boxes of a horse stall, will all hold the contagion for some days, if 

 not weeks, and communicate it to susceptible animals when placed in 

 the same locality 



Terminations. The termination of simple influenza may be death 

 by extreme fever, with failure of the hearts' action; from excessive 



