BUREAU OF ANIMAL INDUSTRY. 225 



There have been made and distributed during the year 33,400 doses 

 of tuberculin, which were supplied to local authorities as a means of 

 cooperation for the suppression of the disease. The greater i^art of 

 this was used by the States of Minnesota, Vermont, and Illinois, but 

 a consideraljle quantity was sent to Michigan, Iowa, New Jersey, and 

 California, and a small amount was supplied to the War Department, 

 the Marine Hospital Service, and to inspectors of the Bureau of 

 Animal Industry for official use. The use of tuberculin as a means 

 of discovering tuberculosis has been less extensive in the United 

 States during the past year than in some previous years, owing, it 

 appears, to a sentiment which has been created against it by those 

 who opi^ose work for the suppression of this disease. The value of 

 this agent has been thoroughly established by scientific investigation 

 and practical use, and no well-informed veterinarian would at the 

 present day undertake to conduct any effectual operations for eradi- 

 cating this disease without its aid in selecting the affected animals. 

 While, therefore, certain States may temporarily abandon the use of 

 tuberculin, they are sure to return to its use when they seriously 

 attempt to control the disease, since its aid is indispensable to intelli- 

 gent and efficient action. 



The Bureau has recently made a test of the herd of cattle belonging 

 to the Government Asylum for the Insane, at St. Elizabeth, D. C, 

 which serves as an additional illustration of the great value of tuber- 

 culin. The presence of tuberculosis in this herd was revealed acci- 

 dentally. A number of the dry cows were" running in a field, where 

 they were undoubtedly bitten by a rabid dog, as 18 of them died of 

 rabies in the course of two weeks. In making the post-mortem exami- 

 nation to discover the cause of death at least 12 of them were found 

 extensively affected with tuberculosis. This led to the entire herd 

 being tested with tuberculin by the pathological division of this 

 Bureau. Of the 102 animals tested, 79 gave a decided reaction, mak- 

 ing the proportion of animals affected more than 77 per cent. As 13 

 of the 23 animals which did not react had but recently been purchased 

 from a farm in Virginia, it will be seen that more than 90 per cent of 

 the old herd reacted to the test. 



Advantage has been taken of this opportunity to test the ineffect- 

 iveness of milk from cows which have reacted to the tuberculin test, 

 but which on physical examination are apparently healthy. A large 

 number of feeding and inoculation experiments are in progress, in 

 which about 700 exiierimental animals are being used. The results, 

 which Avill be of great value from a sanitary j)oint of view, will be 

 submitted for publication as soon as the experiments are completed. 



GENERAL PATHOLOGICAL INVESTIGATIONS. 



During March and April a highly fatal disease aj)peared among the 

 cattle belonging to the Government Asylum for the Insane, at St. Eliz- 

 abeth, D. C. Six or seven dry cows died in the course of two days, 

 exhibiting symj)toms of gastro-enteritis with cerebral complications. 

 A number of other cows became similarh' affected, and in the course 

 of two weeks from the beginning of the outbreak eighteen animals 

 had died, when the disease suddenly stopped. 



A careful investigation in connection with the history of the pres- 

 ence of a supposedly mad dog among the cattle of the affected herd 

 suggested that the disease might be rabies. This diagnosis was sub- 

 AGR 1900 15 



