DOG DISTEMPER. 
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weakly constitution, inbreeding, washing, debilitating diseases, 
parasites, shipping, oestrum, surgical operations, ovarectorny, 
emasculation, docking tails, trimming ears, haemorrhage, 
wounds accidental or otherwise ; in fact, any condition that 
tends to lower the vitality, or expose the animal to sudden 
changes of temperature, would act as a predisposing factor. 
The exciting cause is undoubtedly a micro-organism, but the 
specific agent has not been determined. 
Distemper is one of the most common diseases of the dog ; 
it is most common during the spring and fall, but occurs at any 
period of the year. The germ gains entrance to the system 
through the medium of the air. No doubt the micro-organism 
is almost universally distributed, but requires some extraordi¬ 
nary atmospheric condition to render it so virulent as to attack 
all subjects. Under ordinary atmospheric conditions, it seems 
content to attack only those dogs that are predisposed, and 
occurs as a sporadic or occasional trouble, being in existence 
among dogs at all times of the year; but it is only under spe¬ 
cial conditions that it breaks out in the epidemic form. At the 
same time it is always communicable from one dog to another 
by contagion, or it may be transferred by fomites. 
Manner of Invasion .— Not determined positively, though 
probably by inspired air through the respiratory apparatus, 
also very likely through the alimentary canal, and in rare cases 
the conjunctiva. Dogs, cats and other animals are liable to 
contract this disease at all ages, and under any conditions, but 
predisposition renders them more susceptible. It must be re¬ 
membered that even the healthiest are not exempt. 
Immunity .—One attack renders the animal immune as a 
rule, but it can be contracted more than once. An attack al¬ 
ways confers immunity for a certain period at least. 
Period of Incubation .—Rarely exceeds three days, but varies 
according to the condition in which the exposed dog is in, to a 
more or less extent. During the period intervening between 
the time of exposure, and the actual onset of the attack, the 
dog is often depressed and shivers. The temperature may be 
