SECTION XIII. 
CONSTITUTIONAL DISEASES. 
CHAPTER I. 
DISTEMPER. 
DisTEMPER is an acute infectious disease, characterized by catarrhal inflam- 
mation of the mucous membranes which line the mouth, throat, air-passages, 
stomach and intestinal canal; an eruptive fever of variable duration; great 
prostration ; rapid waste; marked derangement and depression of the nervous 
system; with a strong tendency to recovery in the absence of complications, 
of which there is great liability. 
That the disease is of microbic origin and caused by a specific poison or 
germ cannot be doubted, although the infecting agent has not been, with cer- 
tainty, isolated and identified. In view, however, of the advances made by 
investigators and experimenters during the last decade there are grounds 
for the belief that its bacteriology will ere long be made clear. 
Accepting this theory of causation, it must also be admitted that distem- 
per never originates spontaneously, but is dependent always upon a continued 
propagation of the disease poison or germ, and transmission of the same from 
one to another. That is, that the disease is possible only when communicated 
by infection. Therefore, such influences as improper feeding, poor ventila- 
tion, exposure to cold and damp, which many have considered accountable 
for it, are not actual exciting causes, but merely predisposing or contributing 
causes. In other words, such influences alone are not capable of giving rise 
to this disease. They can only increase the susceptibility of dogs to it, lessen 
their power of resistance to the specific poison or germ, and possibly in some 
degree determine the severity of attacks. 
Among the products of experience are the obvious facts that it is possible 
for the distemper poison or germ to reproduce itself, under favorable condi- 
tions, to an endless degree ; that except in very dry air and place, it retains its 
great vitality and power of infection for a long time outside of the body from 
whence it came; also, that while still virulent it can be conveyed in the air, 
although the distance which it may be so transported is not great, and proba- 
bly limited to a few feet only. 
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