BIOLOGICAL THERAPEUTICS 



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spread of the disease, or to prevent its extension in localities where the 

 disease is very prevalent'. When in such cases an inert vaccine is used, 

 both the veterinarian and stock owner are often at a loss to explain the 

 reason if the disease appears. Unfortunately such eases are quite numer- 

 ous, and from my personal experience in testing out vaccines from vari- 

 ous sources I can state that the failure to keep the vaccines under proper 

 conditions is often responsible for bad results. 



While many different biologic products are being prepared for the 

 prevention and treatment of disease, there are some which stand out 

 prominently over others in their specific action. Many of these products 

 now play an important part in the control of animal plagues, whether for 

 their value as diagnostic agents of obscure or latent disease or as pre- 

 ventive and curative remedies. 



In the following a brief outline is given of the conditions in which 

 the application of biological products has been especially successful. 



ANTHRAX. 

 (Charbon; Splenic Fever, etc.) 



Anthrax is an infectious disease caused by specific bacteria known 

 as anthrax bacilli (B. anthracis), and is usually restricted by conditions 

 of soil and moisture to certain geographic localities. All domestic animals 

 are susceptible to 

 this disease, al- 

 though goats and 

 hog sare much 

 more r e s i s tant 

 than other species. 

 The anthrax ba- 

 cillus is a rod- 

 shaped organism, 

 which in the body 

 of the infected ani- 

 mals multiplies by 

 a simple dividing 

 process, but out- 

 side of the animal 

 and under condi- 

 tions not so favor- 

 able for this form 

 of multiplication it 

 forms spores. The 

 spores under fa- 

 vorable conditions 

 again change into 

 bhe disease produc- 

 ing germs. The 



spores are very resistant and are known to retain their infective 

 qualities for twenty years. In putrid material the bacillus is readily de- 

 stroyed, but the spores are resistant even against such influences. The in- 

 fection as a rule, results .frofli the ingestion of spores by susceptible ani- 

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Bacillus Anthracis. Showing the Capsule Stained 



