52 Blackleg. 



months. Later vaccinations on thousands of animals performed 

 in many sections have shown that the artificial immunity also 

 protects against natural infection. The vaccinations have re- 

 sulted in a large decrease in cases among vaccinated animals 

 (11 to 12 times fewer cases than among non-vaccinated animals) ; 

 besides in the infected localities the percentage of mortality has 

 decreased during recent years, which evidently is owing to the 

 fact that there have been fewer diseased carcasses and less 

 contaminated material to infect the ground. The protective 

 vaccination is now practiced with good results in those districts 

 where the disease usually appears as an epizootic. 



The method was modified by Preisz so that the powdered muscle 

 substance is heated for 6 hours in live steam, and 0.05 gm. is used 

 for the first, and 0.10 gm. for the second vaccination. 



In 1880, Arloing, Cornevin & Thomas subjected 13 head of cattle to protec- 

 tive vaccination at Chaumont before a commission ; when these cattle were later inocu- 

 lated with virulent material they all remained healthy, while out of 12 non-vac- 

 cinated animals 11 acquired blackleg as a result of a similar artificial inoculation, 

 and 9 of them died. 



According to Strebel, out of 82,550 cattle vaccinated during the years 1884 

 to 1898, in Switzerland, 0.75% contracted blackleg, while out of 35,400 non-vac- 

 cinated animals, kept under the same conditions, 2.6% succumbed. According to 

 another compilation by Strebel, during the years 1885 to 1894, out of 325,892 vac- 

 cinated cattle in various countries, 0.056% died from vaccination blackleg, and later 

 0.38% died from spontaneous blackleg. There were 129,705 vaccinated animals kept 

 during the summer on the same pasture with 240,560 unvaccinated animals; out of 

 the former 0.42% and out of the latter 1.76% were the victims of blackleg. Strebel 

 considers vaccination in the tail as less dangerous than in the shoulder, since with 

 the former, 23 out of 107,080 vaccinated animals (0.021%) and with the latter 181 

 animals out of 26,816 (0.67% or 31 times more) died as a result of the vaccina- 

 tion. On the other hand, Suchanta at Salzburg was satisfied with the vaccination 

 in the shoulder. In the canton of Berne in the years 1885 to 1908, out of 463,613 

 vaccinated animals 580 (0.125%) died after vaccination, and 1,915 (0.41%) in the 

 following 14 months (Belavoine). In the Austrian alpine regions, during the year 

 1909, 33,056 head of cattle were vaccinated, out of which, during the pasture sea- 

 son, 114 (0.345%) died, against 1.094% among the unvaccinated herd-mates. 



In Hungary the protective vaccinations have had good effect both on the improved 

 breeds and on the native cattle. First the Lyons vaccine, and later Preisz' vaccine 

 were used. According to Hutyra's compilations, during the years 1893 to 1900, out 

 of 16,679 vaccinated animals 22 (0.13%) were lost. In the year 1907, out of 14,029 

 animals vaccinated in infected herds, 80 died after the first vaccination, and sub- 

 sequently by the end of the year 36 had died ; on the other hand, in previously unin- 

 fected herds, the loss amounted to only 1 and 15 respectively out of 14,148 vaccinated 

 animals. 



Techniciue of Vaccination. The 10 doses (1.0 g.) of vaccine contained in folded 

 paper-wrappers (yellow-red powder) are ground carefully with 5.0 cc. of sterilized 

 water in a small mortar, and the mixture^ is filtered through sterilized, moistened 

 linen cloth. The filtrate is drawn into a syringe 5 cc. capacity made for the pur- 

 pose, and the fluid kept agitated in order to avoid sedimentation. The piston of the 

 syringe is divided into 10 divisions; after filling the syringe the indicator is placed 

 at the 1st division. 



According to the original French method (Lyons), the place of injection is on 

 the lower part of the tail; the first injection is made 3, and the second 2 hand- 

 breadths from the end of the tail. While the animal is secured at the head and 

 at the hind part, the tail is taken up with the left hand, the hair is shaved from 

 the site of injection and the skin disinfected; then the trocar going with the syringe 

 is pushed under the skin to the handle, thereby making a canal about 5cm. long. 

 The trocar is then carefully withdrawn and in its place the dull hollow needle is 

 inserted, and one dose is injected into the canal. Then the needle is pulled out, the 

 place of injection pressed together with the left thumb, the syringe delivered to the 

 assistant, and the injected vaccine pressed upward by means of the right thumb; 

 finally, the tail is bandaged with a narrow linen bandage over the place of injection. 



