Immunization. 53 



The bandage is removed after four hours, although it may safely be left on in cattle 

 kept in the pasture. After 10 to 12 days the animals are again vaccinated in the 

 same manner but with the stronger vaccine. 



Many firms ship emulsions of the vaccine powder in sealed glass tubes for 

 immediate use. Such vaccine is easily contaminated and should be used as soon 

 as possible, but the powder vaccine keeps unchanged for months. 



According to recent experiences, the vaccination, at least on fhe hardy range 

 cattle, may be performed behind the shoulder with the same results and more 

 conveniently (see, however, Strebel's statistics). Here it is also advisable to per- 

 forate the skin by means of a trocar, while the bandage after the injection of 

 course is dispensed with. The second vaccination likewise follows 10 to 12 days 

 later, but on the opposite side of the chest. 



It is advisable to apply the vaccination at the end of winter or in the 

 spring, if possible, before the cattle are sent to pasture. Otherwise the animals 

 are liable to be infected before vaccination, and the summer heat may cause 

 unpleasant complications after tail vaccination, according to the Lyons method, 

 because the animals do not keep the vaccinated part of the body quiet. Calves less 

 than six months old and cattle over 4 years old raised in blackleg districts, as well 

 as pregnant heifers in the last four weeks of pregnancy, should^ not be vaccinated. 

 Sucking calves are not immunized by the vaccination, and old animals as a rule do 

 not contract the disease. 



immediate results of the Taccination. Vaccinations if properly per- 

 formed only caui-e a slight local swelling at the place of injection, which rarely 

 is accompanied by general indisposition and only by a slight rise in the tem- 

 perature. Unpleasant complications are seldom observed and, as a rule, occur only 

 when the vaccination has not been performed with the necessary care and cleanli- 

 ness. Such complications, which usually appear 3 to 6 days after the vaccination, 

 consist in necrosis of the 3 or 4 last vertebra of the tail, bending of the tail, forma- 

 tion of abscesses, inflammation, etc. 



Protective vaccination of sheep. Scheibel vaccinated sheep successfully 

 with vaccine prepared from diseased muscles of sheep. The meat is dried at 30° C. 

 and ground; one half is heated at 100° C. and the other half at 85° C. for 6 

 hours; of this 1.0 gm. is used for every 20 sheep. The vaccination is performed, as 

 with cattle, near the end of the tail, and in docked sheep on the inside of the 

 leg. Such vaccinated animals prove immune against the infection with fresh diseased 

 muscle or blackleg virus. 



II. One inoculation with attenuated virus. According to 

 experiments by Kitt, a powder prepared from diseased muscles, 

 after having been heated for 6 hours in dry air at 85 to 90° C, 

 or still better, in live steam at 97° C, gives a suitable vaccine. 

 One injection of such vaccine into cattle immunizes them suffi- 

 ciently and lastingly, without causing conspicuous symptoms 

 of disease (the vaccine kills sheep in doses from 0.2 to 0.6 gm. ; 

 smaller doses produce only slight fever). 



This method which is conducted in the same way as vac- 

 cination with Lyons vaccine, except that the operation is per- 

 formed in one act, is especially to be recommended for vaccina- 

 tion of the more hardy native cattle, but it also gives satis- 

 factory results in the improved breeds which have less power of 

 resistance. 



In Bavaria, during the years 1898 to 1906, out of 62,178 vaccinated head 

 of cattle 8 died shortly after the vaccination and 134 later, in all 0.22%, while in the 

 first 5 years, on the same pastures out of 23,324 non-vaccinated animals 398 or 

 1.70% died from blackleg (Kitt). In the years 1903 to 1905, out of 25,609 vac- 

 cinated animals 68 or 0.26% died later from natural infection. In Austria, accord- 

 ing to the official reports, in the years 1891 to 1894, 28,855 head of cattle were 

 vaccinated by one inoculation with the Kitt vaccine; out of those 47 or 0.16% died 

 from vaccination blackleg and 86 or 0.29% from spontaneous blackleg. 



In Hungary, in the year 1892, Makoldy vaccinated 230 head of cattle from 

 1 to 4 years old by Kitt's method, one-half belonging to the Hungarian-Sieben- 

 burgen breed, and the other half to the Pinzgau breed. The vaccination itself 



