METHODS OF INFECTION Q7 
Unfortunately the dog habitually has its nose to the 
ground; he smells everything everywhere, and in con- 
sequence becomes especially prone to the baneful effects 
of injurious dust, etc. How else can we account for 
distemper being caught by a dog, which, in its innocence 
and curiosity merely runs into a kennel, stable, or room 
in which a distempered animal had previously been; 
runs out again without touching the walls or eating any- 
thing, and in a few days falls sick? How did Sir E. 
Shackleton’s dogs become infected if not by inhalation, 
as they never left their crates (except on the ship) 
between Northern Canada and England, and yet about 
twenty-two were subjects of distemper upon arrival ? 
Nevertheless, Youatt was correct when he remarked: 
“There is a great deal of caprice about the way in which 
a dog will or will not become infected, for I have more 
than once kept a dog in the foul yard of my hospital 
for several successive weeks, and he has not become 
diseased.” 
Messrs. Sewell, Gray, Parsons, and Flook are all of 
opinion* that distemper is seldom, if ever, communicated 
from the affected to the non-affected by aerial infection. 
The contrary view is held by Friedberger, Frohner, 
Blaine, Glass, Miller, myself, and various others, and 
whoever may be correct, it is at least a wise precaution 
to regard it as transmissible by aerial infection. 
This chapter would not be complete were particular 
stress not laid upon the fact that distemper can only arise 
from the presence of its specific contagium, and that a cold 
wil] not and cannot produce it. As a contributory or 
predisposing factor, chills among other conditions are 
forces to be reckoned with, and will be discussed in the 
section dealing with predisposing causes. One writer 
declared that “ whilst distemper is highly contagious, it 
* Proceedings of National Veterinary Association. 
