114 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



nation of hay cut from swampy meadows proved it to be the source 

 of infection in an outbreak of anthrax investigated by the bureau. A 

 number of outbreaks of anthrax in various parts of the country have 

 been investigated and measures taken for control in cooperation with 

 State officials. 



CEREBROSPINAL MENINGITIS OR FORAGE POISONING. 



Sporadic outbreaks of forage poisoning or cerebrospinal menin- 

 gitis of horses were studied in the tidewater sections of Maryland and 

 Virginia in the fall and winter. Excellent material for study was 

 obtained, and various experiments were made by inoculating culture 

 media in the laboratory and by feeding and inoculating animals. 



Intestinal contents of horses killed while in a dying condition with 

 the natural affection were used to drench well horses at the Bethesda 

 Experiment Station, but with negative results. Laboratory experi- 

 mental animals fed with feed purposely contaminated with this 

 intestinal material remained well. Work on the disease has been 

 continued in cooperation with the Bureau of Chemistry, and further 

 feeding tests have been conducted with damaged, immature, and 

 moldy corn, but with the usual negative results. 



The similarity of some of the symptoms of the disease of horses to 

 botulism of man suggested experiments with a strain of Bacillus 

 hotulinus known to possess pathogenic qualities, and horses and 

 donkeys were fed with feed contaminated with minute quantities of 

 the culture and toxin, with fatal results. The facts disclosed are 

 very significant, in that a disease is induced which in some respects 

 closely resembles forage poisoning, but additional work will be 

 required to place this disease definitely and to prove or disprove its 

 relationship to the spontaneous forage poisonings met with so fre- 

 quently in veterinary practice. 



DOURINE INVESTIGATIONS. 



The complement-fixation test for dourine has continued to be ex- 

 tensively employed for diagnosis, 45,100 samples of blood serum hav- 

 ing been received and diagnosed by this method, of which 1,400, or 

 3.1 per cent, gave positive reactions. 



During the year the microscopic agglutination test for the diag- 

 nosis of dourine was devised, using as agglutinating fluid a suspen- 

 sion of live trypanosomes. This test was used as a supplementary 

 test to the complement fixation, and is of particular value in certain 

 cases, greatly facilitating the rapid diagnosis of the large number of 

 samples tested. 



GLANDERS INVESTIGATIONS. 



The complement-fixation test for glanders was applied to the serum 

 of 1,647 animals, of which 253, or 15 per cent, gave positive reactions. 



Cooperative work in the control of an outbreak of glanders at New- 

 port News, Va., from which point a large number of horses and 

 mules were shipped abroad, was carried on. About 300 samples of 

 blood serum were tested by the complement-fixation test. The post- 

 mortem examinations substantiated the results of the serum test in 

 practically every case. 



