PREDISPOSING CAUSES 43, 
Influence of Acclimatisation.—Recently imported or 
unacclimatised dogs are particularly predisposed to dis- 
temper, since it is a fact that dogs born and bred in one 
locality or country appear to acquire a certain immunity 
to the one or more strains of infection which contaminate 
its surroundings, but when moved into an entirely new 
area become subjects of the disease. 
_ Influence of Faulty Hygiene—Crowding many animals 
together, even under good hygienic conditions, but 
especially when associated with careless management, 
permitting of insufficient space and ventilation, and dis- 
regard of thorough cleanliness and disinfection, prove 
a sure method of courting the contagium. Similarly, 
lack of exercise, unnatural systems of feeding and rear- 
ing, Starvation, fatigue from super-abundant or enforced 
exercise, or from prolonged travelling by rail or sea, 
all tend to lower the system, and render the animal 
more susceptible. 
Influence of Chills and Debilitating Condttions.—Prob- 
ably the chief predisposing cause is chill, brought on by 
exposure in various ways—e.g.: (1) A dog may be play- 
fully thrown into water, presumably to teach it to swim; 
it emerges wet, and shivers in a cold wind. (2) It may 
be bathed and insufficiently dried. (3) It may be inad- 
vertently locked out in the open all night. (4) Or a 
wretched yard dog may occupy a leaky, bedless, or 
draughty kennel in severe wintry weather. But what- 
ever the cause, the result is the same, and should the dog 
at this time come into contact with the infection of dis- 
temper, he may contract the disease, notwithstanding 
the fact that he may have previously suffered from it. 
Then we have as contributory factors the debility 
arising from the ignorant use of purgatives and vermi- 
fuges, and, less frequently, that following severe surgical 
operations, parturition, and prostrating diseases. 
