No. 6. DEPARTMENT OF AGRICULTURE. 109 



re:port of thk state) ve^tbrinarian 



FOR 1907. 



Hakrisburg, Pa., Jantiary /, igo8. 



Hon. N. B. Ci'itchfield, Secretary of Agriculture, Hai'rtsbiirg, Pa.: 



Sir: I have the honor to present in the following report on the 



work of the office of the State Veterinarian and upon the work of 



the State Livestock Sanitarv Board for the vear 1907. 



The work of the State Livestock Sanitary Board continues to increase very 

 rapidly. Fortunately, the last legislature provided for enlarging the staff of 

 this office, without which it would be quite impossible to respond to half of the 

 demands for help that are received from owners of livestock. Under the au- 

 thorization of the act approved May 25th, 1907, a Deputy State Veterinarian 

 has been appointed. The Department of Agriculture and the State are for- 

 tunate in having obtained in this connection the services of Dr. Louis A. Klein. 

 Dr. Klein was appointed by the Governor, October 15th, 1907. His long exper- 

 ience in public veterinary work, under both State and Federal authority has 

 enabled him to at once assume important responsibilities. 



A large part of the executive work in connection with the administration of 

 the law pertaining- to meat hygiene falls to Dr. Klein. The meat hygiene ser- 

 vice will be referred to later. It may be said in this place, however, that the 

 law is working well and the further we proceed to carry it out the more evi- 

 dent becomes the necessity for it. 



Two new diseases have been discovered in this State during the year. One of 

 these, epizootic lymphangitis, is a disease of horses and the other, chronic 

 bacterial dysentery, is a disease of cattle. These discoveries are of especial 

 interest and importance because neither of these diseases has ever before been 

 diagnosed in the United States, or, indeed, in any part of the American con- 

 tinent. It seems to be highly probable that both diseases exist in other states. 

 It is creditable to the field and laboratory staff of the State Livestock Sanitary 

 Board that the true nature of both of these infections have been recognized 

 here in advance of such recognition in other states where the diseases prevail. 

 The diseases are quite different in character, but both are essentially chronic. 

 It is believed that sanitary measures can be conducted with success against 

 both of these newly discovered infections now that the first step, that is the 

 determination of their nature, has been made. 



The subject of tuberculosis of cattle continues to be of great importance. 

 There is growing interest among herd owners in reference to tuberculosis and 

 public health officials are demanding more and more that this disease be ex- 

 terminated among milk and meat producing animals. These combined influences 

 lead to the utilization to the utmost of the resources of the State Livestock 

 Sanitary Board that may be directed against tuberculosis. 



Vaccination against tuberculosis has received a large amount of study at 

 the laboratory and at the experimental farm of the State Livestock Sanitary 

 Board. Many methods for vaccinating cattle against tuberculgsis have been 

 tried. Some of these are original, others are as used elsewhere. A commer- 

 cial tuberculosis vaccine that is widedly advertised has been experimented 

 with, among others. It has been found that the claims made for the com- 

 mercial vaccine are exaggerated and misleading. The method that Iras been de- 

 veloped at the experimental farm that has given best results has been used in 

 a considerable number of breeding herds and is being employed more each year. 



The vaccine that is used in our practical work on farms consists of a living 

 tubercle virus, the organism being of human type and very attenuated. This 

 virus is incapable of infecting cattle. It is administered by intravenous injec- 

 tion. A second vaccination is made with a larger dose six weeks after the first 

 vaccination and a third vaccination is made after a similar interval. Experi- 

 rnents have shown that the immunity that results from such treatment is of 

 high grade and is sufficient to protect animals under conditions of unusually 

 severe exposure to intimate contact with extensively tuberculous cows. The 

 resistance so produced may be depended on for a period of approximately two 

 years. Some animals so vaccinated retain their resistance for a considerably 

 longer period. It appears, however, that the limit of dependable immunity 

 from the method that is used at this time is around four months. This period 

 is long enough to be of considerable practical value. For instance, if one is 

 endeavoring to re-organize, on a healthy basis, a breeding herd that has been 

 found to be more or less extensively infected with tuberculosis, it may not 

 economically be possible, or desirable, to dispose immediately of all infected 

 animals, and to thoroughly disinfect the premises requires considerable time. 



