86 STRANGLES. 



7. They may all be jpropagated by contagion. — So, under 

 certain conditions, may strangles be propagated. 



It may be perfectly true that irrefragable proof cannot be 

 adduced to demonstrate tbat strangles is in every case, and in 

 all manifestations, contagious. No more can it be proved that 

 other well-established contagious diseases are in all cases 

 transmitted by contagion. When appearing amongst horses 

 where the evil and deteriorating influences incident to over- 

 crowding, imperfect dietetic and generally bad sanitary condi- 

 tions are not brought into operation, strangles does not so 

 often -manifest that low or typhoid form in which it mainly 

 exhibits its contagious properties. 



When appearing simultaneously amongst a number of 

 animals, its origin is usually attributed, by those who deny its 

 contagious character, to the ' something in the air ' theory, to 

 occult and inappreciable atmospheric influences, or, it may be, 

 to the general operation of the same depressing and vitiating 

 influences which have developed it in the first. 



It should never be forgotten that even diseases which are 

 certainly contagious are only surely transmitted in this way 

 when other conditions in those to be acted upon are favourable 

 for the reception and development of the contagium or 

 vitiating element ; while at the same time evidence can be 

 adduced to satisfy most minds that it is highly probable, to 

 place the statement in the mildest form, that in certain in- 

 stances strangles is capable of transmission from the diseased 

 to the healthy. 



Most veterinarians who have practised in the country and in 

 breeding districts can call to mind many instances where 

 strangles has been introduced to studs of liorses, and amongst 

 these propagated, by the purchase of a fresh animal labouring 

 under the disease. 



I have also observed that, when strangles breaks out 

 amongst young horses, they generally become affected in greater 

 numbers within a given time, when they are in actual contact 

 or close proximity, than when they are kept at different parts 

 of the same homestead, or where they have greater liberty and 

 are less restricted to close company with the others suftering 

 from the disease. I have, moreover, found that not onl}' has an 

 imported diseased animal brought the aflbction amongst others 



