DIAGNOSTIC INOCULATION. 225 



toxins (serums) become agglutinated (clumped) and sink 

 to the bottom of the liquid in which they were suspended. 

 This knowledge has also been made use of in the diagnosis of 

 glanders. The technique, according to Schuetz, is as follows : 



Disinfect the skin overlying the jugular vein of the sus- 

 pected horse, insert a hypodermic needle and withdraw about 

 30 to 50 cc of blood into a sterilized flask, then seal care- 

 fully. The serum is allowed to separate and is then diluted 

 to various strengths by the addition of a physiological salt 

 solution. 



The test fluid is prepared from virulent cultures of 

 glanders bacilli that have been heated in a thermostat for two 

 hours at a temperature of 60° C. [140° F.] in order to kill 

 the bacteria. To this material is added a sufficient quantity 

 of carbolized sodium chloride solution to make an emulsion 

 which, in reflected light, has a slightly milky appearance. 



Two cubic centimeters of the test fluid are added to vary- 

 ing proportions of the blood serum of the suspected horse 

 and kept in a thermostat at 30° C. [86° R] for from 24 to 30 

 hours. If the serum agglutinates the bacilli when diluted in 

 the proportion of 1 :1000, or more, the horse from which it 

 was obtained is regarded as glandered. x\n agglutination re- 

 sulting from a dilution of the serum of 1 :500 to 1 :1000 indi- 

 cates probable infection, and an agglutination power of less 

 than 1.500 indicates the absence of infection. The making of 

 a successful agglutination test requires not only fresh and 

 virulent cultures of glanders bacilli, but also a certain degree 

 of skill and the necessary experience. For this reason it can 

 be successfully performed in bacteriological laboratories only. 

 The function of the practicing veterinarian, therefore, should 

 be limited to the collection of the serum from the suspected 

 animal which should then be forwarded to the proper state 

 authorities, board of live stock commissioners or board of 

 health. 



