266 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



The blood for the transfusions was supplied by cattle that had 

 been immunized by the methods of Pearson and Von Behring and 

 that had resisted infection after a long-continued exposure to the 

 tuberculous environment previously described, in which about 86 

 per cent of all exposed, untreated, or 'check cattle contracted tuber- 

 culosis. 



As far as the very small number of cattle used justifies draw- 

 ing conclusions, the blood-transfusion experiments gave wholly 

 negative results and hold out no encouragement as being a means 

 by which tuberculosis can be treated or the resistance to infection 

 strengthened. The treated animals may have been too far ad- 

 vanced in the disease to derive benefit from any form of treatment, 

 but the animals which received blood to immunize them apparently 

 were as susceptible to infection as those that had received no treat- 

 ment. 



GENERAL CONCLUSIONS. 



The only conclusion to which we are entitled from this work 

 and -from careful study of the writings of others on the subject 

 of protective inoculation against tuberculosis may be stated as fol- 

 lows: Though results have been obtained which are very encour- 

 aging to the investigator and which prompt him to strive onward 

 with renewed vigor and hope, no system of bovo-vaccination has 

 reached a stage at the present time that justifies its use in common 

 practice. 



TUBERCULOSIS, ITS CAUSE, ITS EFFECT AND MODE OF DISTRIBUTION. 



What is Tuberculosis? A transmissable disease caused by a 

 specific kind of bacteria. A transmissible disease is one produced 

 by a living organism which enters the body of an animal and 

 grows therein, producing harmful changes, which may or may not 

 cause the death of the animal. The organisms leave the body of 

 the diseased animal in various ways and enter the body of a sec- 

 ond, healthy animal. Thus, each case of a transmissible disease 

 must come from a pre-existing case of the same disease. Sometimes 

 the connection between the different cases is easily traced, at other 

 times not. 



What Other Names are Applied to Tuberculosis? Consump- 

 tion and phthisis are terms used to designate tuberculosis of the 

 lungs in man. By scrofula was formerly meant tuberculosis of the 

 glands of the neck. Lupus is tuberculosis of the skin, and cold 

 abscesses and hip-joint disease are likely to be tuberculosis of the 

 bones. Grapes and pearl disease are names often applied by the 

 butcher to certain types of the disease in cattle. 



What Animals Have Tuberculosis? All warm blooded and 

 some cold blooded animals. In man it is the most important of 

 all transmissible diseases, which include such diseases as typhoid 

 fever, diptheria, scarlet fever, small pox, measles, mumps, etc. In 

 the northern portion of this country it is the most important dis- 

 ease of cattle. Of the domestic animals, cattle, hogs and fowls are 

 most often affected, sheep, horses, dogs and cats but rarely. Most 

 of the wild animals in captivity die of tuberculosis. 



