70 ANNUAL REPORT. OF THE Off. Doc. 



quarter to a single definite source. The experience of England in 

 completely eradicating rabies and the repression of numerous 

 outbreaks in Pennsylvania by the enforcement of quarantine regula- 

 tions should encourage us to continue efforts to restrict this disease 

 to the narrowest possible limits. 



In Ma}', Ur. M. P. IJavenel resigned his position as bacteriologist 

 to the State Livestock Sanitary Board, in order to accept a posi- 

 tion of large responsibility with the Phipps' Institute for the Study 

 Treatment and Prevention of Tuberculosis. Dr. Ravenel had been in 

 charge of the laboratory of the State Livestock Sanitary Board for 

 a period of eight years, during which time a great deal of important 

 original work was carried on and published. Dr. Ravenel's resigna- 

 tion was received with regret. His former assistant. Dr. S. H. Gili- 

 land, was chosen to succeed him. Dr. Gilliland has been associated 

 with the laboratory work of this Board for a number of years, and 

 for three years has been closely identified with the investigations that 

 have been carried on in relation to the immunization of -cattle against 

 tuberculosis. 



The work of the laboratory in connection with the examination and 

 diagnosis of specimens submitted by veternarians has increased 

 steadily. Perhaps the greatest increase has been in relation to the 

 examination of animals suspected of having been afflicted with 

 rabies. Seventy specimens from animals suspected of having been 

 infected with this disease were submitted for examination; 60 were 

 from dogs, 4 from horses, 4 from cows and 2 from cats. In 49 cases, a 

 positive diagnosis of rabies was made. This diagnosis was made in 

 most cases from a microscopic examination of nerve tissue. This 

 quick method of diagnosis has been very carefully studied in the la- 

 boratory of this Board; it has been controlled by diagnostic inocula- 

 tion and its accuracy has been thoroughly proven. The great advant- 

 ages of a rapid diagnosis when a person has been bitten by a sus- 

 pected animal, or when other animals have been bitten, are obvious. 

 Sometimes, however, the material is not suitable for a diagnosis by 

 microscopic examination, and in such cases the older method of diag- 

 sis, inoculation, has to be resorted to. This method of diagnosis is 

 not used excepting when persons or animals have been bitten by 

 the animal submitted for diagnosis. 



Other diseases diagnosed by the laboratory examination of speci- 

 mens are anthrax, glanders, blackquarter, tuberculosis, hemorrhagic 

 septicaemia, diseases of poultry and parasitic diseases. A number 

 of samples of milk and butter have been submitted for bacteriolo- 

 gical examination for various purposes. Nearly one thousand doses 

 of anthrax vaccine hav6 been made; 16,795 C. C. tuberculin have 

 been sent out from the laboratory during the year, and almost 300 

 doses of mallein. 



Experiments upon the vaccination of cattle against tuberculosis 

 have been continued. The farm in Delaware county that was rented 

 for the accommodation of the experimental animals has proven to 

 be well adapted to the purpose in view. 



In this experiment an effort has been made to keep the animals 

 under what may be regarded as practical farm conditions. Cattle 

 have been vaccinated and are exposed to constant daily contact 

 with tubercular cattle. Unvaccinated cattle are exposed in the 

 same way, for the purpose of furnishing comparisons with the van 



