INFECTIOUS ABOKTION IN. SWINE 421 



of one of these pigs. The bacillus was present in this instance 

 in very small numbers. 



On March 27, 1916, the tails of these sows were carefully 

 washed, shaved and disinfected, the ends cut off, and 25 cc. of 

 blood taken. The blood serum of each of these sows caused 

 complete agglutination of a known culture of B. abortus Bang in 

 a dilution of 1 :100, with 75 per cent agglutination in a dilution 

 of 1:250, and the complement was completely fixed with 0.02 

 cc. of the serum. Serum from a normal hog tested at the same 

 time did not agglutinate the agglutinating fluid in any dilution, 

 nor did it fix the complement. 



The slipping of the pigs produced no after effects upon the 

 sows that we could notice. They will be kept under observa- 

 tion for some time. 



Taking into consideration all the results mentioned in this 

 paper, we may conclude that the Bacillus abortus (Bang) is an 

 etiological factor in infectious abortion of sows. Whether or 

 not it is the only etiological factor, will have to be determined 

 by further investigations. This is the second time, so far as 

 we know, that the Bacillus abortus has been associated naturally 

 with aborting animals of a species other than the cow. The first 

 was discovered by Dr. Surface^ when he found the disease epi- 

 zootic among guinea pigs which were being reared in an inclosure 

 in which inoculation experiments were being carried on with 

 the Bang bacillus. Some of the Utter from the cages containing 

 the inoculated pigs had gotten into the pens of breeding pigs 

 and caused the spread of the disease. 



SUMMARY 



1. Epizootic infectious abortion occurs occasionally among 

 sows, though not so frequently as among cows and mares. 



2. Previous to the time of this investigation, no etiological 

 factor connected with the disease in the sow had been discovered. 



3. In this investigation the B. abortus of Bang, the organism 



5 F. M. Surface, Bovine Infectious Abortion Epizootic Among Guinea Pigs, 

 Journal of Infectious Diseases, 1912, 11, no. 3, p. 464. 



