American Veterinary Review, 
JUNE, 1884. 
ORIGINAL ARTICLES. 
CONTAGIOUS DISEASES OF ANIMALS IN THE UNITED STATES. 
A Paper read at the Chicago Convention by Prof. J. Law, F.R.C.V.S., of 
Cornell University. 
{Continued from page 72.) 
Measures for Suppression and Extinction. 
In devising means 'for suppressing any plague we must give 
paramount attention to two great considerations: First, can we 
render the animal system insusceptible or non-receptive of the 
poison ; and Second , can we destroy every vestige of the poison ? 
No plague can be propagated in the absence of susceptible sub¬ 
jects. The lung plague virus is perfectly harmless to a com¬ 
munity of horses, sheep or pigs. So it is to a great extent to 
cattle that have already been infected by it and have fully 
recovered from the disease. Just as a man does not readily con¬ 
tract small-pox a second time, so an ox does not usually suffer a 
second time from lung plague. I would not trouble you with 
this part of the subject, but that some advocate the restriction of 
this plague by producing this comparative insusceptibility in the 
animals exposed. 
Methods of Seeking Insusceptibility. 
This insusceptibility to lung plague may be secured more or 
less perfectly, by : 
