BUREAU OF ANIMAL INDUSTRY. 113 



GLANDERS INVESTIGATIONS. 



In connection with cooperative work with State authorities for the 

 control of glanders of horses and mules the complement-fixation test 

 was applied to 1,411 samples of serums, 251, or 17.8 per cent, of 

 which gave positive reactions to the test. 



Cooperative work was done with the War Department in the control 

 and eradication of glanders among Army horses and mules. The 

 complement-fixation test was applied to 800 samples of serum from 

 horses and mules at various remount depots and cantonments 

 throughout the country. These samples were largely from animals 

 giving an indefinite reaction to the ophthalmic mallein test, or were 

 sent in for a confirmation of positive findings with the allergic tests, 

 and also in cases in which every possible precaution to exclude glan- 

 ders infection was to be used. Stock solutions of glanders antigen for 

 the complement-fixation test were furnished to various Army labo- 

 ratories, together with details of the technic of the test as conducted 

 by the bureau. 



Limited tests, on glanderous mules, of a mallein prepared from 

 strains of Bacillus mallei isolated from lesions in mules did not show 

 this mallein to be any more specific than mallein made from strains 

 of the organism from horses. 



DOURINE. 



The complement- fixation test has continued to be extensively 

 employed for the diagnosis of dourine of horses, 45,651 samples of 

 serum having been tested, 1,018, or 2.23 per cent, of which gave posi- 

 tive reactions to the test. 



A second multiple pipette has been devised for handling serum 

 samples, whereby large numbers of samples can be tested easily in 

 the daily routine with less help than in previous years. An improved 

 method in the preparation of the dourine antigen by the use of dis- 

 tilled water to eliminate the red blood cells in collecting the trypa- 

 nosomes has been found very satisfactory. 



Cooperative work was done with the War Department in the test- 

 ing for dourine of a number of samples of serum from mares which 

 were to be used for breeding purposes to insure their being free from 

 this disease. 



ABORTION DISEASE. 



Efforts to acquire more definite information regarding infectious 

 abortion of cattle have been continued, the procuring of further 

 evidence as to how the disease is disseminated, and the possibilities 

 of immunization as a means of control having received particular 

 attention. Numerous methods of obtaining information have been 

 employed, namely, (1) the utilization of cattle in experiments where 

 the environment could be controlled, (2) the observation of infected 

 herds where the disease has existed for a variable length of time, and 

 (3) the bacteriological and histological study of the tissues of sus- 

 pected animals obtained from abattoirs. 



By making repeated serological tests of numerous herds, both 

 where the infection was of recent origin and where it was known to 

 have existed for several years, a marked difference has been noted 

 in the rapidity with which the disease spreads, even though the herds 



