HEMORRHAGIC SKI 'TICK MIA. 3 



spring the entire herd of buffaloes was vaccinated with material 

 prepared from (he pun- cultures obtained in Washington. Two 

 vaccines of different strengths were prepared. The vaccine for the 

 first inoculation was prepared by growing the organism 5 days at 

 42.5° C. (108° F.), while the second was cultivated at (lie same tem- 

 perature for only 2 days. 



This experiment was probably the first instance in which auto- 

 genic vaccines were used in the United States for the prevention of 

 hemorrhagic septicemia, and its success was so marked thai similar 

 steps were taken afterwards to check outbreaks among cattle, sheep, 

 and goats, so that at the present time bacterins for the inoculation of 

 infected herds and flocks are prepared by several firms which manu- 

 facture biological products and may be purchased in all parts of the 

 country. 



Anthrax appeared in several counties in Texas in 1913, and during 

 the investigation of the outbreak two cases of -hemorrhagic septi- 

 cemia were discovered, one in a horse and the other in a sheep. The 

 organisms recovered were identical with the bacilli, which recency 

 have been recovered from outbreaks of hemorrhagic septicemia in 

 cattle and goats. 



During the fall and winter of 1915-16 many cases were reported 

 to the Bureau of Animal Industry in which young stock cattle that 

 had been purchased in carload lots at some of the large stockyards 

 had developed hemorrhagic septicemia within a few days after their 

 arrival. At the same time two flocks of sheep and one of goats were 

 found to be affected with the disease. Cultures of either the hemor- 

 rhagic septicemia group of organisms or cultures closely related to 

 the colon or paratyphoid B group were recovered from these cases. 



CAUSE OF THE DISEASE. 



The organism of hemorrhagic septicemia, the Bacillus hipolaris 

 septicus, belongs to the group in which the bacilli of chicken cholera, 

 swine plague, and rabbit septicemia are to be found. This group is 

 known also by the name Pasteurella. The individual organism is 

 an ovoid, nonmotile, polar-staining bacterium with rounded ends, 

 1/38000 of an inch wide by 1/20000 of an inch long, sometimes seen 

 in pairs or chains, but usually appearing singly. It stains readily 

 with the stains usually used in bacteriological work, and in many 

 cases shows deep staining at each end, while the middle of the bacillus 

 shows but little coloring. It forms no gas and quickly destroys itself 

 while growing on solid culture media by the development of acids. 



The organism may be cultivated readily in bouillon and on agar 

 and gelatin. The reaction of the medium should be slightly alkalin 

 or neutral. It does not liquefy gelatin, coagulate milk, or produce 

 indol. 



