380 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



6. SWINE PLAGUE IN OTHER ANIMALS. 



Professor Lotv succeeded iu communicating swine pla.Gue to slieop and 

 rabbits, and Professor lOein snccessiully inoculated rats, and so there 

 is no donbt that tbose animals can contract tlie disease and become the 

 means of its spreading. It may therefore be ahnost superfiuons to men- 

 tion that I have seen, while acting as inspector of cattle in the Union 

 Stock Yard, several rats evidently diseased Avith swine plague. Pro- 

 fessor Law's experiment iu inoculating a dog has not been as successful 

 as he desii'ed, and there is no doubt that dogs possess comparatively 

 little susceptibility, but they are, notwithstanding, able to contract the 

 disease, as will be seen from the following : Mr. David Moore, a farmer 

 residing two miles north of Champaign, is known to be a reliable man 

 and a close observer of all the symptoms of swine plague in its various' 

 phases. La'st year he lost nearly every hog he had on his place, and 

 this spring he lost fourteen pigs. Late in the Ml, so Mr. ]\Ioore informed 

 me, his dog, a pointer, feasted on the unburied carcasses of hogs that 

 had died of swine plague. In less than two weelcs the dog was taken 

 sick and showed symptoms identical, Mr. Moore says, with those exhib- 

 ited by his diseased hogs. In about two weeks the dog was ema- 

 ciated to a mere skeleton. It was over four years old, a-nd Mr. Moore 

 is positive that the disease was communicated swine plague and not 

 common dog distemper, a disease which, by the way, was not prevail- 

 ing in the neighborhood, and which very seldom attacks dogs over four 

 years old. Of course this was not a case witnessed by myself, but I con- 

 sidered it worth relating, because I know Mr. Moore and cannot doubt 

 his veracity. 



7. THE CONTAGIOUS OR INFECTIOUS PRINCIPLE.— ITS SPREADING, ITS 

 PROPAGATION, AND ITS VITALITY. 



That the hacilU suis and their germs constitute the contagious or the 

 infectious principle and the true cause of the disease has been conlirmed 

 not only by the result of my exi)eriments with pigs Nos. 1 and 2, but 

 also by numerous clinical observations. 1. Xone of the inoculations 

 made since August 1 produce<l any local reaction except tlie second in- 

 oculation of heifer 'So. 2, which was followed by a very slight local reac- 

 tion, consisting in a scarcely perceptible local swelling, easily accounted 

 for by the manner in which the operation was performed. The point of 

 the hyiiodermic syringe used was very weak and rather dull, and an 

 opening through the skin had to be made with a knife, whicli caused a 

 wound sufficient to produce such a slight swelling. In heifer No. 1, in- 

 oculated on the same day, and with double the amount of the same ma- 

 terial, but by means of another hypodermic syringe with a point strong 

 and sharp enough to peuetrate the skin, no swelling whatever appeared. 

 If the infectious prineii)le consisted in something of the nature of a 

 viras, or in something that possesses chemical properties, or does not 

 need to propagate and to multiply before it can act, a local reaction 

 would have taken place. 



On the other hand, if an animal infected with, swine plague receives 

 a wound or an external lesion sufficient to cause congestion and iutiam- 

 mation, the morbid process is ahnost sure to localize in the congested or 

 inflamed jjarts. Further, if the infections principle is introduced into a 

 wound or a lesion with inHaraed, swelled, or congested borders — for 

 instance, in a wound caused by ringing or by castration, &c. — the morbid 

 process is sure to develop in the iutiamed or congested borders of that 



