240 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



increased interest that is being manifested in the live-stock industry, 

 as is evidenced by the ^adiial replacement of the more resistant com- 

 mon range cattle by higher grade stock, the necessity for immuniza- 

 tion against this virulent disease appears to be more thoroughly 

 appreciated. 



The results of vaccinations for the fiscal year ending June 30, 1910, 

 as reported to the bureau by stock owners who have used the vaccine, 

 are equally as satisfactory as in former years. An examination of 

 the statistics serves to emphasize the degree of immunity that is 

 established by vaccination of the susceptible cattle. 



AUTOGENIC VACCINES. 



Quite a number of cases of abscess, poll evil, and fistulous withers 

 have been successfully treated with autogenic vaccines made directly 

 from pus germs isolated from the afTected animals. The mode of 

 procedure was as follows: Sterile, wide-mouthed bottles were fur- 

 nished practitioners with instructions to sterilize the exterior sur- 

 faces and collect the pus from the last pus that could be expressed 

 from the abscess, or in the case of a closed abscess, to aspirate the 

 pus by means of a sterile hypodermic syringe. This material was 

 then examined microscopically for the presence of staphlococci or 

 streptococci. In some instances the material aspirated from closed 

 abscess proved sterile, and in others there were so few of the germs 

 that it became necessary to incubate the material overnight to cause 

 their multiplication so that good, luxuriant growths could be obtained. 

 Four or five slanted agar tubes were then inseminated thoroughly and 

 incubated two days, in case the predominating forms were strepto- 

 cocci, or one day in case staphylococci were in greater abundance. 

 The growths were then washed down with normal salt solutions and 

 devitalized by heating in a water bath at 55° C. for one hour. The 

 resulting emulsion or suspension of killed bacteria constitutes the 

 vaccine, and is infected subcutaneously, under aseptic precautions, 

 into the root of the neck at its lowest part where the skin is thin and 

 where the resulting reaction can be readily seen. At the same time 

 the ordinary surgical measures, such as dependent openings and 

 drainage, are carried out, as the vaccination treatment should be con- 

 sidered adjunctive only. 



It is necessary to know the approximate number of bacteria in the 

 dose of the vaccine, and this is determined by making the vaccine as 

 turbid as a standard tube containing 50,000,000 bacteria per cubic 

 centimeter. An instrument known as a turbidometer has been 

 devised for determining these turbidities. 



Two methods of administration were followed, one in which the 

 dose was very small and repeated every four days until six or seven 

 doses had been given, the other in which the dose was very much 

 larger. In the first method of dosage there is httle or no reaction 

 from the injections, and the beneficial effects are sometimes delayed. 

 In the second method the reaction is pronounced, consisting of 

 swelling at the site of operation and increase of the discharge from the 

 abscess, it being necesssary to wait for several days for the reaction to 

 subside before giving the next dose. On account of this there is 

 little gained in point of time, and moreover the owner is sometimes 

 averse to allowing the treatment to proceed when he sees his animal 

 apparently "made worse," even if only temporarily so. 



